How can I add all the columnar values by associative key? Note that key sets are dynamic.
Input array:
Array
(
[0] => Array
(
[gozhi] => 2
[uzorong] => 1
[ngangla] => 4
[langthel] => 5
)
[1] => Array
(
[gozhi] => 5
[uzorong] => 0
[ngangla] => 3
[langthel] => 2
)
[2] => Array
(
[gozhi] => 3
[uzorong] => 0
[ngangla] => 1
[langthel] => 3
)
)
Desired result:
Array
(
[gozhi] => 10
[uzorong] => 1
[ngangla] => 8
[langthel] => 10
)
You can use array_walk_recursive() to get a general-case solution for your problem (the one when each inner array can possibly have unique keys).
$final = array();
array_walk_recursive($input, function($item, $key) use (&$final){
$final[$key] = isset($final[$key]) ? $item + $final[$key] : $item;
});
Example with array_walk_recursive() for the general case
Also, since PHP 5.5 you can use the array_column() function to achieve the result you want for the exact key, [gozhi], for example :
array_sum(array_column($input, 'gozhi'));
Example with array_column() for the specified key
If you want to get the total sum of all inner arrays with the same keys (the desired result that you've posted), you can do something like this (bearing in mind that the first inner array must have the same structure as the others) :
$final = array_shift($input);
foreach ($final as $key => &$value){
$value += array_sum(array_column($input, $key));
}
unset($value);
Example with array_column() in case all inner arrays have the same keys
If you want a general-case solution using array_column() then at first you may consider to get all unique keys , and then get the sum for each key :
$final = array();
foreach($input as $value)
$final = array_merge($final, $value);
foreach($final as $key => &$value)
$value = array_sum(array_column($input, $key));
unset($value);
Example with array_column() for the general case
$sumArray = array();
foreach ($myArray as $k=>$subArray) {
foreach ($subArray as $id=>$value) {
isset($sumArray[$id]) || $sumArray[$id] = 0;
$sumArray[$id]+=$value;
}
}
print_r($sumArray);
Use this snippet:
$key = 'gozhi';
$sum = array_sum(array_column($array,$key));
Here is a solution similar to the two others:
$acc = array_shift($arr);
foreach ($arr as $val) {
foreach ($val as $key => $val) {
$acc[$key] += $val;
}
}
But this doesn’t need to check if the array keys already exist and doesn’t throw notices neither.
It can also be done using array_map :
$rArray = array(
0 => array(
'gozhi' => 2,
'uzorong' => 1,
'ngangla' => 4,
'langthel' => 5
),
1 => array(
'gozhi' => 5,
'uzorong' => 0,
'ngangla' => 3,
'langthel' => 2
),
2 => array(
'gozhi' => 3,
'uzorong' => 0,
'ngangla' => 1,
'langthel' => 3
),
);
$sumResult = call_user_func_array('array_map', array_merge(['sum'], $rArray));
function sum()
{
return array_sum(func_get_args());
}
$newarr=array();
foreach($arrs as $value)
{
foreach($value as $key=>$secondValue)
{
if(!isset($newarr[$key]))
{
$newarr[$key]=0;
}
$newarr[$key]+=$secondValue;
}
}
Another version, with some benefits below.
$sum = ArrayHelper::copyKeys($arr[0]);
foreach ($arr as $item) {
ArrayHelper::addArrays($sum, $item);
}
class ArrayHelper {
public function addArrays(Array &$to, Array $from) {
foreach ($from as $key=>$value) {
$to[$key] += $value;
}
}
public function copyKeys(Array $from, $init=0) {
return array_fill_keys(array_keys($from), $init);
}
}
I wanted to combine the best of Gumbo's, Graviton's, and Chris J's answer with the following goals so I could use this in my app:
a) Initialize the 'sum' array keys outside of the loop (Gumbo). Should help with performance on very large arrays (not tested yet!). Eliminates notices.
b) Main logic is easy to understand without hitting the manuals. (Graviton, Chris J).
c) Solve the more general problem of adding the values of any two arrays with the same keys and make it less dependent on the sub-array structure.
Unlike Gumbo's solution, you could reuse this in cases where the values are not in sub arrays. Imagine in the example below that $arr1 and $arr2 are not hard-coded, but are being returned as the result of calling a function inside a loop.
$arr1 = array(
'gozhi' => 2,
'uzorong' => 1,
'ngangla' => 4,
'langthel' => 5
);
$arr2 = array(
'gozhi' => 5,
'uzorong' => 0,
'ngangla' => 3,
'langthel' => 2
);
$sum = ArrayHelper::copyKeys($arr1);
ArrayHelper::addArrays($sum, $arr1);
ArrayHelper::addArrays($sum, $arr2);
It can also be done using array_walk:
function array_sum_values(array $input, $key) {
$sum = 0;
array_walk($input, function($item, $index, $params) {
if (!empty($item[$params[1]]))
$params[0] += $item[$params[1]];
}, array(&$sum, $key)
);
return $sum;
}
var_dump(array_sum_values($arr, 'gozhi'));
Not so readable like previous solutions but it works :)
Go through each item of the array and sum values to previous values if they exist, if not just assign the value.
<?php
$array =
[
[
'a'=>1,
'b'=>1,
'c'=>1,
],
[
'a'=>2,
'b'=>2,
],
[
'a'=>3,
'd'=>3,
]
];
$result = array_reduce($array, function($carry, $item) {
foreach($item as $k => $v)
$carry[$k] = $v + ($carry[$k] ?? 0);
return $carry;
}, []);
print_r($result);
Output:
Array
(
[a] => 6
[b] => 3
[c] => 1
[d] => 3
)
Or just loop through each sub array, and group the values for each column. Eventually summing them:
foreach($array as $subarray)
foreach($subarray as $key => $value)
$grouped[$key][] = $value;
$sums = array_map('array_sum', $grouped);
Here's a version where the array keys may not be the same for both arrays, but you want them all to be there in the final array.
function array_add_by_key( $array1, $array2 ) {
foreach ( $array2 as $k => $a ) {
if ( array_key_exists( $k, $array1 ) ) {
$array1[$k] += $a;
} else {
$array1[$k] = $a;
}
}
return $array1;
}
We need to check first if array key does exist.
CODE:
$sum = array();
foreach ($array as $key => $sub_array) {
foreach ($sub_array as $sub_key => $value) {
//If array key doesn't exists then create and initize first before we add a value.
//Without this we will have an Undefined index error.
if( ! array_key_exists($sub_key, $sum)) $sum[$sub_key] = 0;
//Add Value
$sum[$sub_key]+=$value;
}
}
print_r($sum);
OUTPUT With Array Key Validation:
Array
(
[gozhi] => 10
[uzorong] => 1
[ngangla] => 8
[langthel] => 10
)
OUTPUT Without Array Key Validation:
Notice: Undefined index: gozhi in F:\web\index.php on line 37
Notice: Undefined index: uzorong in F:\web\index.php on line 37
Notice: Undefined index: ngangla in F:\web\index.php on line 37
Notice: Undefined index: langthel in F:\web\index.php on line 37
Array
(
[gozhi] => 10
[uzorong] => 1
[ngangla] => 8
[langthel] => 10
)
This is a bad practice although it prints the output. Always check first if key does exist.
Simple example with array_reduce()
$numbers = [10,20,30];
$total = 0;
foreach ($numbers as $number) {
$total += $number;
}
echo $total; // 60
=>
$numbers = [10,20,30];
$total = array_reduce($numbers, function ($previous, $current) {
return $previous + $current;
});
echo $total; // 60
With assoc array:
$carts = [
['item' => 'A', 'qty' => 2, 'price' => 10],
['item' => 'B', 'qty' => 3, 'price' => 20],
['item' => 'C', 'qty' => 5, 'price' => 30]
];
$total = array_reduce(
$carts,
function ($prev, $item) {
return $prev + $item['qty'] * $item['price'];
}
);
echo $total; // 155
More info => https://www.phptutorial.net/php-tutorial/php-array_reduce/
For those who landed here and are searching for a solution that merges N arrays AND also sums the values of identical keys found in the N arrays, I've written this function that works recursively as well. (See: https://gist.github.com/Nickology/f700e319cbafab5eaedc)
Example:
$a = array( "A" => "bob", "sum" => 10, "C" => array("x","y","z" => 50) );
$b = array( "A" => "max", "sum" => 12, "C" => array("x","y","z" => 45) );
$c = array( "A" => "tom", "sum" => 8, "C" => array("x","y","z" => 50, "w" => 1) );
print_r(array_merge_recursive_numeric($a,$b,$c));
Will result in:
Array
(
[A] => tom
[sum] => 30
[C] => Array
(
[0] => x
[1] => y
[z] => 145
[w] => 1
)
)
Here's the code:
<?php
/**
* array_merge_recursive_numeric function. Merges N arrays into one array AND sums the values of identical keys.
* WARNING: If keys have values of different types, the latter values replace the previous ones.
*
* Source: https://gist.github.com/Nickology/f700e319cbafab5eaedc
* #params N arrays (all parameters must be arrays)
* #author Nick Jouannem <nick#nickology.com>
* #access public
* #return void
*/
function array_merge_recursive_numeric() {
// Gather all arrays
$arrays = func_get_args();
// If there's only one array, it's already merged
if (count($arrays)==1) {
return $arrays[0];
}
// Remove any items in $arrays that are NOT arrays
foreach($arrays as $key => $array) {
if (!is_array($array)) {
unset($arrays[$key]);
}
}
// We start by setting the first array as our final array.
// We will merge all other arrays with this one.
$final = array_shift($arrays);
foreach($arrays as $b) {
foreach($final as $key => $value) {
// If $key does not exist in $b, then it is unique and can be safely merged
if (!isset($b[$key])) {
$final[$key] = $value;
} else {
// If $key is present in $b, then we need to merge and sum numeric values in both
if ( is_numeric($value) && is_numeric($b[$key]) ) {
// If both values for these keys are numeric, we sum them
$final[$key] = $value + $b[$key];
} else if (is_array($value) && is_array($b[$key])) {
// If both values are arrays, we recursively call ourself
$final[$key] = array_merge_recursive_numeric($value, $b[$key]);
} else {
// If both keys exist but differ in type, then we cannot merge them.
// In this scenario, we will $b's value for $key is used
$final[$key] = $b[$key];
}
}
}
// Finally, we need to merge any keys that exist only in $b
foreach($b as $key => $value) {
if (!isset($final[$key])) {
$final[$key] = $value;
}
}
}
return $final;
}
?>
Here you have how I usually do this kind of operations.
// We declare an empty array in wich we will store the results
$sumArray = array();
// We loop through all the key-value pairs in $myArray
foreach ($myArray as $k=>$subArray) {
// Each value is an array, we loop through it
foreach ($subArray as $id=>$value) {
// If $sumArray has not $id as key we initialize it to zero
if(!isset($sumArray[$id])){
$sumArray[$id] = 0;
}
// If the array already has a key named $id, we increment its value
$sumArray[$id]+=$value;
}
}
print_r($sumArray);
You can try this:
$c = array_map(function () {
return array_sum(func_get_args());
},$a, $b);
and finally:
print_r($c);
this works great on my laravel project
print_r($Array); // your original array
$_SUM = [];
// count($Array[0]) => if the number of keys are equall in all arrays then do a count of index 0 etc.
for ($i=0; $i < count($Array[0]); $i++) {
$_SUM[] = $Array[0][$i] + $Array[1][$i]; // do a for loop on the count
}
print_r($_SUM); // get a sumed up array
$sumArray = array();
foreach ($myArray as $k => $subArray) {
foreach ($subArray as $id => $value) {
if (!isset($sumArray[$id])) {
$sumArray[$id] = 0;
}
$sumArray[$id]+=$value;
}
}
$sumArray = array();
foreach ($myArray as $k=>$subArray) {
foreach ($subArray as $id=>$value) {
if(!isset($sumArray[$id])){
$sumArray[$id] =$value;
}else {
$sumArray[$id]+=$value;
}
}
}
print_r($sumArray);
`
For example, you can pluck all fields from a result like this below.
I am picking out the 'balance' from an array and save to a variable
$kii = $user->pluck('balance');
then on the next line u can sum like this:
$sum = $kii->sum();
Hope it helps.
Code here:
$temp_arr = [];
foreach ($a as $k => $v) {
if(!is_null($v)) {
$sum = isset($temp_arr[$v[0]]) ? ((int)$v[5] + $sum) : (int)$v[5];
$temp_arr[$v[0]] = $sum;
}
}
return $temp_arr;
Result:
{SEQ_OK: 1328,SEQ_ERROR: 561}
Related
Array1
(
[a]=>1; [b]=>2; [c]=>3
)
Array2
(
[a]=>1;[b] =>1
)
Required result:
Array1
(
[a]=>2; [b]=>3; [c]=>3
)
How do i append Array1 with the values of Array2 based on their key? Thanks.
You can try something like this:
foreach($array2 as $key2 => $val2){
if(key_exists($key2, $array1)) {
$array1[$key2] += $val2;
} else {
$array1[$key2] = $val2;
}
}
Part of the issue would be that array 1 may not have all of the same keys as array 2. So, an array of all keys from both original arrays is needed, then loop through those keys, check if it exists in either original array, and finally add it to the final combined array.
<?php
$array1 = array('a' => 1, 'b' => 2, 'c' => 3);
$array2 = array('a' => 1, 'b' => 2, 'd' => 3);
$finalarr = array();
$arrkeys = array_merge(array_keys($array1), array_keys($array2));
$arrkeys = array_unique($arrkeys);
foreach($arrkeys as $key) {
$finalarr[$key] = 0;
if (isset($array1[$key])) {
$finalarr[$key] += $array1[$key];
}
if (isset($array2[$key])) {
$finalarr[$key] += $array2[$key];
}
}
print_r($finalarr);
?>
foreach($array1 as $key=>$value){
if(isset($array2[$key])){
$array1[$key] = $array1[$key] + $array2[$key];
}
}
Not the most elegant way, which would use array_walk or array_map, but I like to see and know exactly what's going on. This will give you what you are looking for.
First sum the values of the common keys and after that, add the others key in the other array:
foreach ($array2 as $k2 => $a2){
if (isset($array1[$k2])){
$array1[$k2]+=$a2;
unset($array2[$k2]);
}
}
$array1 += $array2;
Something like:
$result = array();
function ParseArray(array $array, array &$result)
{
foreach ($array as $k => $v) {
if (!array_key_exists($k, $result) {
$result[$k] = $v;
} else {
$result[$k] += $v;
}
}
}
ParseArray($Array1, $result);
ParseArray($Array2, $result);
print_r($result);
You should read about PHP array functions.
$array1 = array(
'a' => 1,
'b' => 2,
'c' => 3,
);
$array2 = array(
'a' => 1,
'b' => 1,
);
array_walk(
$array1,
function (&$value, $key) use ($array2) {
$value += (isset($array2[$key])) ? $array2[$key] : 0;
}
);
var_dump($array1);
How can I insert a new item into an array on any position, for example in the middle of array?
You may find this a little more intuitive. It only requires one function call to array_splice:
$original = array( 'a', 'b', 'c', 'd', 'e' );
$inserted = array( 'x' ); // not necessarily an array, see manual quote
array_splice( $original, 3, 0, $inserted ); // splice in at position 3
// $original is now a b c x d e
If replacement is just one element it is not necessary to put array() around it, unless the element is an array itself, an object or NULL.
RETURN VALUE: To be noted that the function does not return the desired substitution. The $original is passed by reference and edited in place. See the expression array &$array with & in the parameters list .
A function that can insert at both integer and string positions:
/**
* #param array $array
* #param int|string $position
* #param mixed $insert
*/
function array_insert(&$array, $position, $insert)
{
if (is_int($position)) {
array_splice($array, $position, 0, $insert);
} else {
$pos = array_search($position, array_keys($array));
$array = array_merge(
array_slice($array, 0, $pos),
$insert,
array_slice($array, $pos)
);
}
}
Integer usage:
$arr = ["one", "two", "three"];
array_insert(
$arr,
1,
"one-half"
);
// ->
array (
0 => 'one',
1 => 'one-half',
2 => 'two',
3 => 'three',
)
String Usage:
$arr = [
"name" => [
"type" => "string",
"maxlength" => "30",
],
"email" => [
"type" => "email",
"maxlength" => "150",
],
];
array_insert(
$arr,
"email",
[
"phone" => [
"type" => "string",
"format" => "phone",
],
]
);
// ->
array (
'name' =>
array (
'type' => 'string',
'maxlength' => '30',
),
'phone' =>
array (
'type' => 'string',
'format' => 'phone',
),
'email' =>
array (
'type' => 'email',
'maxlength' => '150',
),
)
$a = array(1, 2, 3, 4);
$b = array_merge(array_slice($a, 0, 2), array(5), array_slice($a, 2));
// $b = array(1, 2, 5, 3, 4)
If you want to keep the keys of the initial array and also add an array that has keys, then use the function below:
function insertArrayAtPosition( $array, $insert, $position ) {
/*
$array : The initial array i want to modify
$insert : the new array i want to add, eg array('key' => 'value') or array('value')
$position : the position where the new array will be inserted into. Please mind that arrays start at 0
*/
return array_slice($array, 0, $position, TRUE) + $insert + array_slice($array, $position, NULL, TRUE);
}
Call example:
$array = insertArrayAtPosition($array, array('key' => 'Value'), 3);
This way you can insert arrays:
function array_insert(&$array, $value, $index)
{
return $array = array_merge(array_splice($array, max(0, $index - 1)), array($value), $array);
}
There is no native PHP function (that I am aware of) that can do exactly what you requested.
I've written 2 methods that I believe are fit for purpose:
function insertBefore($input, $index, $element) {
if (!array_key_exists($index, $input)) {
throw new Exception("Index not found");
}
$tmpArray = array();
$originalIndex = 0;
foreach ($input as $key => $value) {
if ($key === $index) {
$tmpArray[] = $element;
break;
}
$tmpArray[$key] = $value;
$originalIndex++;
}
array_splice($input, 0, $originalIndex, $tmpArray);
return $input;
}
function insertAfter($input, $index, $element) {
if (!array_key_exists($index, $input)) {
throw new Exception("Index not found");
}
$tmpArray = array();
$originalIndex = 0;
foreach ($input as $key => $value) {
$tmpArray[$key] = $value;
$originalIndex++;
if ($key === $index) {
$tmpArray[] = $element;
break;
}
}
array_splice($input, 0, $originalIndex, $tmpArray);
return $input;
}
While faster and probably more memory efficient, this is only really suitable where it is not necessary to maintain the keys of the array.
If you do need to maintain keys, the following would be more suitable;
function insertBefore($input, $index, $newKey, $element) {
if (!array_key_exists($index, $input)) {
throw new Exception("Index not found");
}
$tmpArray = array();
foreach ($input as $key => $value) {
if ($key === $index) {
$tmpArray[$newKey] = $element;
}
$tmpArray[$key] = $value;
}
return $input;
}
function insertAfter($input, $index, $newKey, $element) {
if (!array_key_exists($index, $input)) {
throw new Exception("Index not found");
}
$tmpArray = array();
foreach ($input as $key => $value) {
$tmpArray[$key] = $value;
if ($key === $index) {
$tmpArray[$newKey] = $element;
}
}
return $tmpArray;
}
This function by Brad Erickson worked for me for the associative array:
/*
* Inserts a new key/value after the key in the array.
*
* #param $key
* The key to insert after.
* #param $array
* An array to insert in to.
* #param $new_key
* The key to insert.
* #param $new_value
* An value to insert.
*
* #return
* The new array if the key exists, FALSE otherwise.
*
* #see array_insert_before()
*/
function array_insert_after($key, array &$array, $new_key, $new_value) {
if (array_key_exists($key, $array)) {
$new = array();
foreach ($array as $k => $value) {
$new[$k] = $value;
if ($k === $key) {
$new[$new_key] = $new_value;
}
}
return $new;
}
return FALSE;
}
The function source - this blog post. There's also handy function to insert BEFORE specific key.
Based on #Halil great answer, here is simple function how to insert new element after a specific key,
while preserving integer keys:
private function arrayInsertAfterKey($array, $afterKey, $key, $value){
$pos = array_search($afterKey, array_keys($array));
return array_merge(
array_slice($array, 0, $pos, $preserve_keys = true),
array($key=>$value),
array_slice($array, $pos, $preserve_keys = true)
);
}
function insert(&$arr, $value, $index){
$lengh = count($arr);
if($index<0||$index>$lengh)
return;
for($i=$lengh; $i>$index; $i--){
$arr[$i] = $arr[$i-1];
}
$arr[$index] = $value;
}
This is also a working solution:
function array_insert(&$array,$element,$position=null) {
if (count($array) == 0) {
$array[] = $element;
}
elseif (is_numeric($position) && $position < 0) {
if((count($array)+position) < 0) {
$array = array_insert($array,$element,0);
}
else {
$array[count($array)+$position] = $element;
}
}
elseif (is_numeric($position) && isset($array[$position])) {
$part1 = array_slice($array,0,$position,true);
$part2 = array_slice($array,$position,null,true);
$array = array_merge($part1,array($position=>$element),$part2);
foreach($array as $key=>$item) {
if (is_null($item)) {
unset($array[$key]);
}
}
}
elseif (is_null($position)) {
$array[] = $element;
}
elseif (!isset($array[$position])) {
$array[$position] = $element;
}
$array = array_merge($array);
return $array;
}
credits go to:
http://binarykitten.com/php/52-php-insert-element-and-shift.html
Solution by jay.lee is perfect. In case you want to add item(s) to a multidimensional array, first add a single dimensional array and then replace it afterwards.
$original = (
[0] => Array
(
[title] => Speed
[width] => 14
)
[1] => Array
(
[title] => Date
[width] => 18
)
[2] => Array
(
[title] => Pineapple
[width] => 30
)
)
Adding an item in same format to this array will add all new array indexes as items instead of just item.
$new = array(
'title' => 'Time',
'width' => 10
);
array_splice($original,1,0,array('random_string')); // can be more items
$original[1] = $new; // replaced with actual item
Note: Adding items directly to a multidimensional array with array_splice will add all its indexes as items instead of just that item.
You can use this
foreach ($array as $key => $value)
{
if($key==1)
{
$new_array[]=$other_array;
}
$new_array[]=$value;
}
Hint for adding an element at the beginning of an array:
$a = array('first', 'second');
$a[-1] = 'i am the new first element';
then:
foreach($a as $aelem)
echo $a . ' ';
//returns first, second, i am...
but:
for ($i = -1; $i < count($a)-1; $i++)
echo $a . ' ';
//returns i am as 1st element
Try this one:
$colors = array('red', 'blue', 'yellow');
$colors = insertElementToArray($colors, 'green', 2);
function insertElementToArray($arr = array(), $element = null, $index = 0)
{
if ($element == null) {
return $arr;
}
$arrLength = count($arr);
$j = $arrLength - 1;
while ($j >= $index) {
$arr[$j+1] = $arr[$j];
$j--;
}
$arr[$index] = $element;
return $arr;
}
function array_insert($array, $position, $insert) {
if ($position > 0) {
if ($position == 1) {
array_unshift($array, array());
} else {
$position = $position - 1;
array_splice($array, $position, 0, array(
''
));
}
$array[$position] = $insert;
}
return $array;
}
Call example:
$array = array_insert($array, 1, ['123', 'abc']);
$result_array = array();
$array = array("Tim","John","Mark");
$new_element = "Bill";
$position = 1;
for ($i=0; $i<count($array); $i++)
{
if ($i==$position)
{
$result_array[] = $new_element;
}
$result_array[] = $array[$i];
}
print_r($result_array);
// Result will Array([0] => "Tim",[1] => "Bill", [2] => "John",[1] => "Mark")
How to preserve array keys using array_splice()
The answer of #jay.lee is correct, unfortunately it doesn't preserve the keys of an array, as pointed out in the comments:
$original = array(
'a' => 'A',
'b' => 'B',
'c' => 'C',
// insert here
'd' => 'D',
'e' => 'E');
$inserted = array( 'x' => 'X' );
array_splice( $original, 3, 0, $inserted );
print_r($original);
/* Output
Array
(
[a] => A
[b] => B
[c] => C
[0] => X <= the lost key
[d] => D
[e] => E
) */
The simplest way I found to preserve the array keys is to use the array_splice() function and adding the arrays together using + / union operators (also mentioned in the comments of another answer):
$original = array(
'a' => 'A',
'b' => 'B',
'c' => 'C',
// insert here
'd' => 'D',
'e' => 'E');
$inserted = array( 'x' => 'X' );
// Insert before postion 'd'
$before = array_splice( $original, 0, 3 ); // $original contains the left over
// Merge together
$result = $before + $inserted + $original;
print_r($result);
/* Output
Array
(
[a] => A
[b] => B
[c] => C
[x] => X
[d] => D
[e] => E
) */
Note: using array union operators is only safe when dealing with non-numeric keys
Thanks for the correction #mickmackusa
Normally, with scalar values:
$elements = array('foo', ...);
array_splice($array, $position, $length, $elements);
To insert a single array element into your array don't forget to wrap the array in an array (as it was a scalar value!):
$element = array('key1'=>'value1');
$elements = array($element);
array_splice($array, $position, $length, $elements);
otherwise all the keys of the array will be added piece by piece.
You can try it, use this method to make it easy
/**
* array insert element on position
*
* #link https://vector.cool
*
* #since 1.01.38
*
* #param array $original
* #param mixed $inserted
* #param int $position
* #return array
*/
function array_insert(&$original, $inserted, int $position): array
{
array_splice($original, $position, 0, array($inserted));
return $original;
}
$columns = [
['name' => '預約項目', 'column' => 'item_name'],
['name' => '預約時間', 'column' => 'start_time'],
['name' => '預約姓名', 'column' => 'full_name'],
['name' => '連絡電話', 'column' => 'phone'],
['name' => '建立時間', 'column' => 'create_time']
];
$col = ['name' => '預約帳戶', 'column' => 'user_id'];
$columns = array_insert($columns, $col, 3);
print_r($columns);
Print out:
Array
(
[0] => Array
(
[name] => 預約項目
[column] => item_name
)
[1] => Array
(
[name] => 預約時間
[column] => start_time
)
[2] => Array
(
[name] => 預約姓名
[column] => full_name
)
[3] => Array
(
[name] => 報名人數1
[column] => num_of_people
)
[4] => Array
(
[name] => 連絡電話
[column] => phone
)
[5] => Array
(
[name] => 預約帳戶
[column] => user_id
)
[6] => Array
(
[name] => 建立時間
[column] => create_time
)
)
For inserting elements into an array with string keys you can do something like this:
/* insert an element after given array key
* $src = array() array to work with
* $ins = array() to insert in key=>array format
* $pos = key that $ins will be inserted after
*/
function array_insert_string_keys($src,$ins,$pos) {
$counter=1;
foreach($src as $key=>$s){
if($key==$pos){
break;
}
$counter++;
}
$array_head = array_slice($src,0,$counter);
$array_tail = array_slice($src,$counter);
$src = array_merge($array_head, $ins);
$src = array_merge($src, $array_tail);
return($src);
}
This can be done with array_splice however, array_splice fails when inserting an array or using a string key. I wrote a function to handle all cases:
function array_insert(&$arr, $index, $val)
{
if (is_string($index))
$index = array_search($index, array_keys($arr));
if (is_array($val))
array_splice($arr, $index, 0, [$index => $val]);
else
array_splice($arr, $index, 0, $val);
}
If you have regular arrays and nothing fancy, this will do. Remember, using array_splice() for inserting elements really means insert before the start index. Be careful when moving elements, because moving up means $targetIndex -1, where as moving down means $targetIndex + 1.
class someArrayClass
{
private const KEEP_EXISTING_ELEMENTS = 0;
public function insertAfter(array $array, int $startIndex, $newElements)
{
return $this->insertBefore($array, $startIndex + 1, $newElements);
}
public function insertBefore(array $array, int $startIndex, $newElements)
{
return array_splice($array, $startIndex, self::KEEP_EXISTING_ELEMENTS, $newElements);
}
}
After working on this for a few days, here was the easiest solution I could find.
$indexnumbertoaddat // this is a variable that points to the index # where you
want the new array to be inserted
$arrayToAdd = array(array('key' => $value, 'key' => $value)); //this is the new
array and it's values that you want to add. //the key here is to write it like
array(array('key' =>, since you're adding this array inside another array. This
is the point that a lot of answer left out.
array_splice($originalArray, $indexnumbertoaddatt, 0, $arrayToAdd); //the actual
splice function. You're doing it to $originalArray, at the index # you define,
0 means you're just shifting all other index items down 1, and then you add the
new array.
Example:
$arr = array(
'apple' => 'sweet',
'grapefruit' => 'bitter',
'pear' => 'tasty',
'banana' => 'yellow'
);
I want to switch the positions of grapefruit and pear, so the array will become
$arr = array(
'apple' => 'sweet',
'pear' => 'tasty',
'grapefruit' => 'bitter',
'banana' => 'yellow'
)
I know the keys and values of the elements I want to switch, is there an easy way to do this? Or will it require a loop + creating a new array?
Thanks
Just a little shorter and less complicated than the solution of arcaneerudite:
<?php
if(!function_exists('array_swap_assoc')) {
function array_swap_assoc($key1, $key2, $array) {
$newArray = array ();
foreach ($array as $key => $value) {
if ($key == $key1) {
$newArray[$key2] = $array[$key2];
} elseif ($key == $key2) {
$newArray[$key1] = $array[$key1];
} else {
$newArray[$key] = $value;
}
}
return $newArray;
}
}
$array = $arrOrig = array(
'fruit' => 'pear',
'veg' => 'cucumber',
'tuber' => 'potato',
'meat' => 'ham'
);
$newArray = array_swap_assoc('veg', 'tuber', $array);
var_dump($array, $newArray);
?>
Tested and works fine
Here's my version of the swap function:
function array_swap_assoc(&$array,$k1,$k2) {
if($k1 === $k2) return; // Nothing to do
$keys = array_keys($array);
$p1 = array_search($k1, $keys);
if($p1 === FALSE) return; // Sanity check...keys must exist
$p2 = array_search($k2, $keys);
if($p2 === FALSE) return;
$keys[$p1] = $k2; // Swap the keys
$keys[$p2] = $k1;
$values = array_values($array);
// Swap the values
list($values[$p1],$values[$p2]) = array($values[$p2],$values[$p1]);
$array = array_combine($keys, $values);
}
if the array comes from the db, add a sort_order field so you can always be sure in what order the elements are in the array.
This may or may not be an option depending on your particular use-case, but if you initialize your array with null values with the appropriate keys before populating it with data, you can set the values in any order and the original key-order will be maintained. So instead of swapping elements, you can prevent the need to swap them entirely:
$arr = array('apple' => null,
'pear' => null,
'grapefruit' => null,
'banana' => null);
...
$arr['apple'] = 'sweet';
$arr['grapefruit'] = 'bitter'; // set grapefruit before setting pear
$arr['pear'] = 'tasty';
$arr['banana'] = 'yellow';
print_r($arr);
>>> Array
(
[apple] => sweet
[pear] => tasty
[grapefruit] => bitter
[banana] => yellow
)
Not entirely sure if this was mentioned, but, the reason this is tricky is because it's non-indexed.
Let's take:
$arrOrig = array(
'fruit'=>'pear',
'veg'=>'cucumber',
'tuber'=>'potato'
);
Get the keys:
$arrKeys = array_keys($arrOrig);
print_r($arrKeys);
Array(
[0]=>fruit
[1]=>veg
[2]=>tuber
)
Get the values:
$arrVals = array_values($arrOrig);
print_r($arrVals);
Array(
[0]=>pear
[1]=>cucumber
[2]=>potato
)
Now you've got 2 arrays that are numerical. Swap the indices of the ones you want to swap, then read the other array back in in the order of the modified numerical array. Let's say we want to swap 'fruit' and 'veg':
$arrKeysFlipped = array_flip($arrKeys);
print_r($arrKeysFlipped);
Array (
[fruit]=>0
[veg]=>1
[tuber]=>2
)
$indexFruit = $arrKeysFlipped['fruit'];
$indexVeg = $arrKeysFlipped['veg'];
$arrKeysFlipped['veg'] = $indexFruit;
$arrKeysFlipped['fruit'] = $indexVeg;
print_r($arrKeysFlipped);
Array (
[fruit]=>1
[veg]=>0
[tuber]=>2
)
Now, you can swap back the array:
$arrKeys = array_flip($arrKeysFlipped);
print_r($arrKeys);
Array (
[0]=>veg
[1]=>fruit
[2]=>tuber
)
Now, you can build an array by going through the oringal array in the 'order' of the rearranged keys.
$arrNew = array ();
foreach($arrKeys as $index=>$key) {
$arrNew[$key] = $arrOrig[$key];
}
print_r($arrNew);
Array (
[veg]=>cucumber
[fruit]=>pear
[tuber]=>potato
)
I haven't tested this - but this is what I'd expect. Does this at least provide any kind of help? Good luck :)
You could put this into a function $arrNew = array_swap_assoc($key1,$key2,$arrOld);
<?php
if(!function_exists('array_swap_assoc')) {
function array_swap_assoc($key1='',$key2='',$arrOld=array()) {
$arrNew = array ();
if(is_array($arrOld) && count($arrOld) > 0) {
$arrKeys = array_keys($arrOld);
$arrFlip = array_flip($arrKeys);
$indexA = $arrFlip[$key1];
$indexB = $arrFlip[$key2];
$arrFlip[$key1]=$indexB;
$arrFlip[$key2]=$indexA;
$arrKeys = array_flip($arrFlip);
foreach($arrKeys as $index=>$key) {
$arrNew[$key] = $arrOld[$key];
}
} else {
$arrNew = $arrOld;
}
return $arrNew;
}
}
?>
WARNING: Please test and debug this before just using it - no testing has been done at all.
There is no easy way, just a loop or a new array definition.
Classical associative array doesn't define or guarantee sequence of elements in any way. There is plain array/vector for that. If you use associative array you are assumed to need random access but not sequential. For me you are using assoc array for task it is not made for.
yeah I agree with Lex, if you are using an associative array to hold data, why not using your logic handle how they are accessed instead of depending on how they are arranged in the array.
If you really wanted to make sure they were in a correct order, trying creating fruit objects and then put them in a normal array.
There is no easy way to do this. This sounds like a slight design-logic error on your part which has lead you to try to do this when there is a better way to do whatever it is you are wanting to do. Can you tell us why you want to do this?
You say that I know the keys and values of the elements I want to switch which makes me think that what you really want is a sorting function since you can easily access the proper elements anytime you want as they are.
$value = $array[$key];
If that is the case then I would use sort(), ksort() or one of the many other sorting functions to get the array how you want. You can even use usort() to Sort an array by values using a user-defined comparison function.
Other than that you can use array_replace() if you ever need to swap values or keys.
Here are two solutions. The first is longer, but doesn't create a temporary array, so it saves memory. The second probably runs faster, but uses more memory:
function swap1(array &$a, $key1, $key2)
{
if (!array_key_exists($key1, $a) || !array_key_exists($key2, $a) || $key1 == $key2) return false;
$after = array();
while (list($key, $val) = each($a))
{
if ($key1 == $key)
{
break;
}
else if ($key2 == $key)
{
$tmp = $key1;
$key1 = $key2;
$key2 = $tmp;
break;
}
}
$val1 = $a[$key1];
$val2 = $a[$key2];
while (list($key, $val) = each($a))
{
if ($key == $key2)
$after[$key1] = $val1;
else
$after[$key] = $val;
unset($a[$key]);
}
unset($a[$key1]);
$a[$key2] = $val2;
while (list($key, $val) = each($after))
{
$a[$key] = $val;
unset($after[$key]);
}
return true;
}
function swap2(array &$a, $key1, $key2)
{
if (!array_key_exists($key1, $a) || !array_key_exists($key2, $a) || $key1 == $key2) return false;
$swapped = array();
foreach ($a as $key => $val)
{
if ($key == $key1)
$swapped[$key2] = $a[$key2];
else if ($key == $key2)
$swapped[$key1] = $a[$key1];
else
$swapped[$key] = $val;
}
$a = $swapped;
return true;
}
fwiw here is a function to swap two adjacent items to implement moveUp() or moveDown() in an associative array without foreach()
/**
* #param array $array to modify
* #param string $key key to move
* #param int $direction +1 for down | -1 for up
* #return $array
*/
protected function moveInArray($array, $key, $direction = 1)
{
if (empty($array)) {
return $array;
}
$keys = array_keys($array);
$index = array_search($key, $keys);
if ($index === false) {
return $array; // not found
}
if ($direction < 0) {
$index--;
}
if ($index < 0 || $index >= count($array) - 1) {
return $array; // at the edge: cannot move
}
$a = $keys[$index];
$b = $keys[$index + 1];
$result = array_slice($array, 0, $index, true);
$result[$b] = $array[$b];
$result[$a] = $array[$a];
return array_merge($result, array_slice($array, $index + 2, null, true));
}
There is an easy way:
$sourceArray = array(
'apple' => 'sweet',
'grapefruit' => 'bitter',
'pear' => 'tasty',
'banana' => 'yellow'
);
// set new order
$orderArray = array(
'apple' => '', //this values would be replaced
'pear' => '',
'grapefruit' => '',
//it is not necessary to touch all elemets that will remains the same
);
$result = array_replace($orderArray, $sourceArray);
print_r($result);
and you get:
$result = array(
'apple' => 'sweet',
'pear' => 'tasty',
'grapefruit' => 'bitter',
'banana' => 'yellow'
)
function arr_swap_keys(array &$arr, $key1, $key2, $f_swap_vals=false) {
// if f_swap_vals is false, then
// swap only the keys, keeping the original values in their original place
// ( i.e. do not preserve the key value correspondence )
// i.e. if arr is (originally)
// [ 'dog' => 'alpha', 'cat' => 'beta', 'horse' => 'gamma' ]
// then calling this on arr with, e.g. key1 = 'cat', and key2 = 'horse'
// will result in arr becoming:
// [ 'dog' => 'alpha', 'horse' => 'beta', 'cat' => 'gamma' ]
//
// if f_swap_vals is true, then preserve the key value correspondence
// i.e. in the above example, arr will become:
// [ 'dog' => 'alpha', 'horse' => 'gamma', 'cat' => 'beta' ]
//
//
$arr_vals = array_values($arr); // is a (numerical) index to value mapping
$arr_keys = array_keys($arr); // is a (numerical) index to key mapping
$arr_key2idx = array_flip($arr_keys);
$idx1 = $arr_key2idx[$key1];
$idx2 = $arr_key2idx[$key2];
swap($arr_keys[$idx1], $arr_keys[$idx2]);
if ( $f_swap_vals ) {
swap($arr_vals[$idx1], $arr_vals[$idx2]);
}
$arr = array_combine($arr_keys, $arr_vals);
}
function swap(&$a, &$b) {
$t = $a;
$a = $b;
$b = $t;
}
Well it's just a key sorting problem. We can use uksort for this purpose. It needs a key comparison function and we only need to know that it should return 0 to leave keys position untouched and something other than 0 to move key up or down.
Notice that it will only work if your keys you want to swap are next to each other.
<?php
$arr = array(
'apple' => 'sweet',
'grapefruit' => 'bitter',
'pear' => 'tasty',
'banana' => 'yellow'
);
uksort(
$arr,
function ($k1, $k2) {
if ($k1 == 'grapefruit' && $k2 == 'pear') return 1;
else return 0;
}
);
var_dump($arr);
I'll share my short version too, it works with both numeric and associative arrays.
array array_swap ( array $array , mixed $key1 , mixed $key2 [, bool $preserve_keys = FALSE [, bool $strict = FALSE ]] )
Returns a new array with the two elements swapped. It preserve original keys if specified. Return FALSE if keys are not found.
function array_swap(array $array, $key1, $key2, $preserve_keys = false, $strict = false) {
$keys = array_keys($array);
if(!array_key_exists($key1, $array) || !array_key_exists($key2, $array)) return false;
if(($index1 = array_search($key1, $keys, $strict)) === false) return false;
if(($index2 = array_search($key2, $keys, $strict)) === false) return false;
if(!$preserve_keys) list($keys[$index1], $keys[$index2]) = array($key2, $key1);
list($array[$key1], $array[$key2]) = array($array[$key2], $array[$key1]);
return array_combine($keys, array_values($array));
}
For example:
$arr = array_swap($arr, 'grapefruit', 'pear');
I wrote a function with more general purpose, with this problem in mind.
array with known keys
specify order of keys in a second array ($order array keys indicate key position)
function order_array($array, $order) {
foreach (array_keys($array) as $k => $v) {
$keys[++$k] = $v;
}
for ($i = 1; $i <= count($array); $i++) {
if (isset($order[$i])) {
unset($keys[array_search($order[$i], $keys)]);
}
if ($i === count($array)) {
array_push($keys, $order[$i]);
} else {
array_splice($keys, $i-1, 0, $order[$i]);
}
}
}
foreach ($keys as $key) {
$result[$key] = $array[$key];
}
return $result;
} else {
return false;
}
}
$order = array(1 => 'item3', 2 => 'item5');
$array = array("item1" => 'val1', "item2" => 'val2', "item3" => 'val3', "item4" => 'val4', "item5" => 'val5');
print_r($array); -> Array ( [item1] => val1 [item2] => val2 [item3] => val3 [item4] => val4 [item5] => val5 )
print_r(order_array($array, $order)); -> Array ( [item3] => val3 [item5] => val5 [item1] => val1 [item2] => val2 [item4] => val4 )
I hope this is relevant / helpful for someone
Arrays in php are ordered maps.
$arr = array('apple'=>'sweet','grapefruit'=>'bitter','
pear'=>'tasty','banana'=>'yellow');
doesn't mean that that the first element is 'apple'=>'sweet' and the last - 'banana'=>'yellow' just because you put 'apple' first and 'banana' last. Actually, 'apple'=>'sweet' will be the first and
'banana'=>'yellow' will be the second because of alphabetical ascending sort order.
How can I add all the columnar values by associative key? Note that key sets are dynamic.
Input array:
Array
(
[0] => Array
(
[gozhi] => 2
[uzorong] => 1
[ngangla] => 4
[langthel] => 5
)
[1] => Array
(
[gozhi] => 5
[uzorong] => 0
[ngangla] => 3
[langthel] => 2
)
[2] => Array
(
[gozhi] => 3
[uzorong] => 0
[ngangla] => 1
[langthel] => 3
)
)
Desired result:
Array
(
[gozhi] => 10
[uzorong] => 1
[ngangla] => 8
[langthel] => 10
)
You can use array_walk_recursive() to get a general-case solution for your problem (the one when each inner array can possibly have unique keys).
$final = array();
array_walk_recursive($input, function($item, $key) use (&$final){
$final[$key] = isset($final[$key]) ? $item + $final[$key] : $item;
});
Example with array_walk_recursive() for the general case
Also, since PHP 5.5 you can use the array_column() function to achieve the result you want for the exact key, [gozhi], for example :
array_sum(array_column($input, 'gozhi'));
Example with array_column() for the specified key
If you want to get the total sum of all inner arrays with the same keys (the desired result that you've posted), you can do something like this (bearing in mind that the first inner array must have the same structure as the others) :
$final = array_shift($input);
foreach ($final as $key => &$value){
$value += array_sum(array_column($input, $key));
}
unset($value);
Example with array_column() in case all inner arrays have the same keys
If you want a general-case solution using array_column() then at first you may consider to get all unique keys , and then get the sum for each key :
$final = array();
foreach($input as $value)
$final = array_merge($final, $value);
foreach($final as $key => &$value)
$value = array_sum(array_column($input, $key));
unset($value);
Example with array_column() for the general case
$sumArray = array();
foreach ($myArray as $k=>$subArray) {
foreach ($subArray as $id=>$value) {
isset($sumArray[$id]) || $sumArray[$id] = 0;
$sumArray[$id]+=$value;
}
}
print_r($sumArray);
Use this snippet:
$key = 'gozhi';
$sum = array_sum(array_column($array,$key));
Here is a solution similar to the two others:
$acc = array_shift($arr);
foreach ($arr as $val) {
foreach ($val as $key => $val) {
$acc[$key] += $val;
}
}
But this doesn’t need to check if the array keys already exist and doesn’t throw notices neither.
It can also be done using array_map :
$rArray = array(
0 => array(
'gozhi' => 2,
'uzorong' => 1,
'ngangla' => 4,
'langthel' => 5
),
1 => array(
'gozhi' => 5,
'uzorong' => 0,
'ngangla' => 3,
'langthel' => 2
),
2 => array(
'gozhi' => 3,
'uzorong' => 0,
'ngangla' => 1,
'langthel' => 3
),
);
$sumResult = call_user_func_array('array_map', array_merge(['sum'], $rArray));
function sum()
{
return array_sum(func_get_args());
}
$newarr=array();
foreach($arrs as $value)
{
foreach($value as $key=>$secondValue)
{
if(!isset($newarr[$key]))
{
$newarr[$key]=0;
}
$newarr[$key]+=$secondValue;
}
}
Another version, with some benefits below.
$sum = ArrayHelper::copyKeys($arr[0]);
foreach ($arr as $item) {
ArrayHelper::addArrays($sum, $item);
}
class ArrayHelper {
public function addArrays(Array &$to, Array $from) {
foreach ($from as $key=>$value) {
$to[$key] += $value;
}
}
public function copyKeys(Array $from, $init=0) {
return array_fill_keys(array_keys($from), $init);
}
}
I wanted to combine the best of Gumbo's, Graviton's, and Chris J's answer with the following goals so I could use this in my app:
a) Initialize the 'sum' array keys outside of the loop (Gumbo). Should help with performance on very large arrays (not tested yet!). Eliminates notices.
b) Main logic is easy to understand without hitting the manuals. (Graviton, Chris J).
c) Solve the more general problem of adding the values of any two arrays with the same keys and make it less dependent on the sub-array structure.
Unlike Gumbo's solution, you could reuse this in cases where the values are not in sub arrays. Imagine in the example below that $arr1 and $arr2 are not hard-coded, but are being returned as the result of calling a function inside a loop.
$arr1 = array(
'gozhi' => 2,
'uzorong' => 1,
'ngangla' => 4,
'langthel' => 5
);
$arr2 = array(
'gozhi' => 5,
'uzorong' => 0,
'ngangla' => 3,
'langthel' => 2
);
$sum = ArrayHelper::copyKeys($arr1);
ArrayHelper::addArrays($sum, $arr1);
ArrayHelper::addArrays($sum, $arr2);
It can also be done using array_walk:
function array_sum_values(array $input, $key) {
$sum = 0;
array_walk($input, function($item, $index, $params) {
if (!empty($item[$params[1]]))
$params[0] += $item[$params[1]];
}, array(&$sum, $key)
);
return $sum;
}
var_dump(array_sum_values($arr, 'gozhi'));
Not so readable like previous solutions but it works :)
Go through each item of the array and sum values to previous values if they exist, if not just assign the value.
<?php
$array =
[
[
'a'=>1,
'b'=>1,
'c'=>1,
],
[
'a'=>2,
'b'=>2,
],
[
'a'=>3,
'd'=>3,
]
];
$result = array_reduce($array, function($carry, $item) {
foreach($item as $k => $v)
$carry[$k] = $v + ($carry[$k] ?? 0);
return $carry;
}, []);
print_r($result);
Output:
Array
(
[a] => 6
[b] => 3
[c] => 1
[d] => 3
)
Or just loop through each sub array, and group the values for each column. Eventually summing them:
foreach($array as $subarray)
foreach($subarray as $key => $value)
$grouped[$key][] = $value;
$sums = array_map('array_sum', $grouped);
Here's a version where the array keys may not be the same for both arrays, but you want them all to be there in the final array.
function array_add_by_key( $array1, $array2 ) {
foreach ( $array2 as $k => $a ) {
if ( array_key_exists( $k, $array1 ) ) {
$array1[$k] += $a;
} else {
$array1[$k] = $a;
}
}
return $array1;
}
We need to check first if array key does exist.
CODE:
$sum = array();
foreach ($array as $key => $sub_array) {
foreach ($sub_array as $sub_key => $value) {
//If array key doesn't exists then create and initize first before we add a value.
//Without this we will have an Undefined index error.
if( ! array_key_exists($sub_key, $sum)) $sum[$sub_key] = 0;
//Add Value
$sum[$sub_key]+=$value;
}
}
print_r($sum);
OUTPUT With Array Key Validation:
Array
(
[gozhi] => 10
[uzorong] => 1
[ngangla] => 8
[langthel] => 10
)
OUTPUT Without Array Key Validation:
Notice: Undefined index: gozhi in F:\web\index.php on line 37
Notice: Undefined index: uzorong in F:\web\index.php on line 37
Notice: Undefined index: ngangla in F:\web\index.php on line 37
Notice: Undefined index: langthel in F:\web\index.php on line 37
Array
(
[gozhi] => 10
[uzorong] => 1
[ngangla] => 8
[langthel] => 10
)
This is a bad practice although it prints the output. Always check first if key does exist.
Simple example with array_reduce()
$numbers = [10,20,30];
$total = 0;
foreach ($numbers as $number) {
$total += $number;
}
echo $total; // 60
=>
$numbers = [10,20,30];
$total = array_reduce($numbers, function ($previous, $current) {
return $previous + $current;
});
echo $total; // 60
With assoc array:
$carts = [
['item' => 'A', 'qty' => 2, 'price' => 10],
['item' => 'B', 'qty' => 3, 'price' => 20],
['item' => 'C', 'qty' => 5, 'price' => 30]
];
$total = array_reduce(
$carts,
function ($prev, $item) {
return $prev + $item['qty'] * $item['price'];
}
);
echo $total; // 155
More info => https://www.phptutorial.net/php-tutorial/php-array_reduce/
For those who landed here and are searching for a solution that merges N arrays AND also sums the values of identical keys found in the N arrays, I've written this function that works recursively as well. (See: https://gist.github.com/Nickology/f700e319cbafab5eaedc)
Example:
$a = array( "A" => "bob", "sum" => 10, "C" => array("x","y","z" => 50) );
$b = array( "A" => "max", "sum" => 12, "C" => array("x","y","z" => 45) );
$c = array( "A" => "tom", "sum" => 8, "C" => array("x","y","z" => 50, "w" => 1) );
print_r(array_merge_recursive_numeric($a,$b,$c));
Will result in:
Array
(
[A] => tom
[sum] => 30
[C] => Array
(
[0] => x
[1] => y
[z] => 145
[w] => 1
)
)
Here's the code:
<?php
/**
* array_merge_recursive_numeric function. Merges N arrays into one array AND sums the values of identical keys.
* WARNING: If keys have values of different types, the latter values replace the previous ones.
*
* Source: https://gist.github.com/Nickology/f700e319cbafab5eaedc
* #params N arrays (all parameters must be arrays)
* #author Nick Jouannem <nick#nickology.com>
* #access public
* #return void
*/
function array_merge_recursive_numeric() {
// Gather all arrays
$arrays = func_get_args();
// If there's only one array, it's already merged
if (count($arrays)==1) {
return $arrays[0];
}
// Remove any items in $arrays that are NOT arrays
foreach($arrays as $key => $array) {
if (!is_array($array)) {
unset($arrays[$key]);
}
}
// We start by setting the first array as our final array.
// We will merge all other arrays with this one.
$final = array_shift($arrays);
foreach($arrays as $b) {
foreach($final as $key => $value) {
// If $key does not exist in $b, then it is unique and can be safely merged
if (!isset($b[$key])) {
$final[$key] = $value;
} else {
// If $key is present in $b, then we need to merge and sum numeric values in both
if ( is_numeric($value) && is_numeric($b[$key]) ) {
// If both values for these keys are numeric, we sum them
$final[$key] = $value + $b[$key];
} else if (is_array($value) && is_array($b[$key])) {
// If both values are arrays, we recursively call ourself
$final[$key] = array_merge_recursive_numeric($value, $b[$key]);
} else {
// If both keys exist but differ in type, then we cannot merge them.
// In this scenario, we will $b's value for $key is used
$final[$key] = $b[$key];
}
}
}
// Finally, we need to merge any keys that exist only in $b
foreach($b as $key => $value) {
if (!isset($final[$key])) {
$final[$key] = $value;
}
}
}
return $final;
}
?>
Here you have how I usually do this kind of operations.
// We declare an empty array in wich we will store the results
$sumArray = array();
// We loop through all the key-value pairs in $myArray
foreach ($myArray as $k=>$subArray) {
// Each value is an array, we loop through it
foreach ($subArray as $id=>$value) {
// If $sumArray has not $id as key we initialize it to zero
if(!isset($sumArray[$id])){
$sumArray[$id] = 0;
}
// If the array already has a key named $id, we increment its value
$sumArray[$id]+=$value;
}
}
print_r($sumArray);
You can try this:
$c = array_map(function () {
return array_sum(func_get_args());
},$a, $b);
and finally:
print_r($c);
this works great on my laravel project
print_r($Array); // your original array
$_SUM = [];
// count($Array[0]) => if the number of keys are equall in all arrays then do a count of index 0 etc.
for ($i=0; $i < count($Array[0]); $i++) {
$_SUM[] = $Array[0][$i] + $Array[1][$i]; // do a for loop on the count
}
print_r($_SUM); // get a sumed up array
$sumArray = array();
foreach ($myArray as $k => $subArray) {
foreach ($subArray as $id => $value) {
if (!isset($sumArray[$id])) {
$sumArray[$id] = 0;
}
$sumArray[$id]+=$value;
}
}
$sumArray = array();
foreach ($myArray as $k=>$subArray) {
foreach ($subArray as $id=>$value) {
if(!isset($sumArray[$id])){
$sumArray[$id] =$value;
}else {
$sumArray[$id]+=$value;
}
}
}
print_r($sumArray);
`
For example, you can pluck all fields from a result like this below.
I am picking out the 'balance' from an array and save to a variable
$kii = $user->pluck('balance');
then on the next line u can sum like this:
$sum = $kii->sum();
Hope it helps.
Code here:
$temp_arr = [];
foreach ($a as $k => $v) {
if(!is_null($v)) {
$sum = isset($temp_arr[$v[0]]) ? ((int)$v[5] + $sum) : (int)$v[5];
$temp_arr[$v[0]] = $sum;
}
}
return $temp_arr;
Result:
{SEQ_OK: 1328,SEQ_ERROR: 561}
How would you flip 90 degrees (transpose) a multidimensional array in PHP? For example:
// Start with this array
$foo = array(
'a' => array(
1 => 'a1',
2 => 'a2',
3 => 'a3'
),
'b' => array(
1 => 'b1',
2 => 'b2',
3 => 'b3'
),
'c' => array(
1 => 'c1',
2 => 'c2',
3 => 'c3'
)
);
$bar = flipDiagonally($foo); // Mystery function
var_dump($bar[2]);
// Desired output:
array(3) {
["a"]=>
string(2) "a2"
["b"]=>
string(2) "b2"
["c"]=>
string(2) "c2"
}
How would you implement flipDiagonally()?
Edit: this is not homework. I just want to see if any SOers have a more creative solution than the most obvious route. But since a few people have complained about this problem being too easy, what about a more general solution that works with an nth dimension array?
i.e. How would you write a function so that:
$foo[j][k][...][x][y][z] = $bar[z][k][...][x][y][j]
?(ps. I don't think 12 nested for loops is the best solution in this case.)
function transpose($array) {
array_unshift($array, null);
return call_user_func_array('array_map', $array);
}
Or if you're using PHP 5.6 or later:
function transpose($array) {
return array_map(null, ...$array);
}
With 2 loops.
function flipDiagonally($arr) {
$out = array();
foreach ($arr as $key => $subarr) {
foreach ($subarr as $subkey => $subvalue) {
$out[$subkey][$key] = $subvalue;
}
}
return $out;
}
I think you're referring to the array transpose (columns become rows, rows become columns).
Here is a function that does it for you (source):
function array_transpose($array, $selectKey = false) {
if (!is_array($array)) return false;
$return = array();
foreach($array as $key => $value) {
if (!is_array($value)) return $array;
if ($selectKey) {
if (isset($value[$selectKey])) $return[] = $value[$selectKey];
} else {
foreach ($value as $key2 => $value2) {
$return[$key2][$key] = $value2;
}
}
}
return $return;
}
Transposing an N-dimensional array:
function transpose($array, &$out, $indices = array())
{
if (is_array($array))
{
foreach ($array as $key => $val)
{
//push onto the stack of indices
$temp = $indices;
$temp[] = $key;
transpose($val, $out, $temp);
}
}
else
{
//go through the stack in reverse - make the new array
$ref = &$out;
foreach (array_reverse($indices) as $idx)
$ref = &$ref[$idx];
$ref = $array;
}
}
$foo[1][2][3][3][3] = 'a';
$foo[4][5][6][5][5] = 'b';
$out = array();
transpose($foo, $out);
echo $out[3][3][3][2][1] . ' ' . $out[5][5][6][5][4];
Really hackish, and probably not the best solution, but hey it works.
Basically it traverses the array recursively, accumulating the current indicies in an array.
Once it gets to the referenced value, it takes the "stack" of indices and reverses it, putting it into the $out array. (Is there a way of avoiding use of the $temp array?)
Codler's answer fails for a single-row matrix (e.g. [[1,2]]) and also for the empty matrix ([]), which must be special-cased:
function transpose(array $matrix): array {
if (!$matrix) return [];
return array_map(count($matrix) == 1 ? fn ($x) => [$x] : null, ...$matrix);
}
(note: PHP 7.4+ syntax, easy enough to adapt for older versions)
I got confronted with the same problem. Here is what i came up with:
function array_transpose(array $arr)
{
$keys = array_keys($arr);
$sum = array_values(array_map('count', $arr));
$transposed = array();
for ($i = 0; $i < max($sum); $i ++)
{
$item = array();
foreach ($keys as $key)
{
$item[$key] = array_key_exists($i, $arr[$key]) ? $arr[$key][$i] : NULL;
}
$transposed[] = $item;
}
return $transposed;
}
I needed a transpose function with support for associative array:
$matrix = [
['one' => 1, 'two' => 2],
['one' => 11, 'two' => 22],
['one' => 111, 'two' => 222],
];
$result = \array_transpose($matrix);
$trans = [
'one' => [1, 11, 111],
'two' => [2, 22, 222],
];
And the way back:
$matrix = [
'one' => [1, 11, 111],
'two' => [2, 22, 222],
];
$result = \array_transpose($matrix);
$trans = [
['one' => 1, 'two' => 2],
['one' => 11, 'two' => 22],
['one' => 111, 'two' => 222],
];
The array_unshift trick did not work NOR the array_map...
So I've coded a array_map_join_array function to deal with record keys association:
/**
* Similar to array_map() but tries to join values on intern keys.
* #param callable $callback takes 2 args, the intern key and the list of associated values keyed by array (extern) keys.
* #param array $arrays the list of arrays to map keyed by extern keys NB like call_user_func_array()
* #return array
*/
function array_map_join_array(callable $callback, array $arrays)
{
$keys = [];
// try to list all intern keys
array_walk($arrays, function ($array) use (&$keys) {
$keys = array_merge($keys, array_keys($array));
});
$keys = array_unique($keys);
$res = [];
// for each intern key
foreach ($keys as $key) {
$items = [];
// walk through each array
array_walk($arrays, function ($array, $arrKey) use ($key, &$items) {
if (isset($array[$key])) {
// stack/transpose existing value for intern key with the array (extern) key
$items[$arrKey] = $array[$key];
} else {
// or stack a null value with the array (extern) key
$items[$arrKey] = null;
}
});
// call the callback with intern key and all the associated values keyed with array (extern) keys
$res[$key] = call_user_func($callback, $key, $items);
}
return $res;
}
and array_transpose became obvious:
function array_transpose(array $matrix)
{
return \array_map_join_array(function ($key, $items) {
return $items;
}, $matrix);
}
We can do this by using Two foreach. Traveling one array and another array to create new arrayLike This:
$foo = array(
'a' => array(
1 => 'a1',
2 => 'a2',
3 => 'a3'
),
'b' => array(
1 => 'b1',
2 => 'b2',
3 => 'b3'
),
'c' => array(
1 => 'c1',
2 => 'c2',
3 => 'c3'
)
);
$newFoo = [];
foreach($foo as $a => $k){
foreach($k as $i => $j){
$newFoo[$i][]= $j;
}
}
Check The Output
echo "<pre>";
print_r($newFoo);
echo "</pre>";
Before I start, I'd like to say thanks again to #quazardus for posting his generalised solution for tranposing any two dimenional associative (or non-associative) array!
As I am in the habit of writing my code as tersely as possible I went on to "minimizing" his code a little further. This will very likely not be to everybody's taste. But just in case anyone should be interested, here is my take on his solution:
function arrayMap($cb, array $arrays) // $cb: optional callback function
{ $keys = [];
array_walk($arrays, function ($array) use (&$keys)
{ $keys = array_merge($keys, array_keys($array)); });
$keys = array_unique($keys); $res = [];
foreach ($keys as $key) {
$items = array_map(function ($arr) use ($key)
{return isset($arr[$key]) ? $arr[$key] : null; },$arrays);
$res[$key] = call_user_func(
is_callable($cb) ? $cb
: function($k, $itms){return $itms;},
$key, $items);
}
return $res;
}
Now, analogous to the PHP standard function array_map(), when you call
arrayMap(null,$b);
you will get the desired transposed matrix.
This is another way to do the exact same thing which #codler s answer does. I had to dump some arrays in csv so I used the following function:
function transposeCsvData($data)
{
$ct=0;
foreach($data as $key => $val)
{
//echo count($val);
if($ct< count($val))
$ct=count($val);
}
//echo $ct;
$blank=array_fill(0,$ct,array_fill(0,count($data),null));
//print_r($blank);
$retData = array();
foreach ($data as $row => $columns)
{
foreach ($columns as $row2 => $column2)
{
$retData[$row2][$row] = $column2;
}
}
$final=array();
foreach($retData as $k=>$aval)
{
$final[]=array_replace($blank[$k], $aval);
}
return $final;
}
Test and output reference: https://tutes.in/how-to-transpose-an-array-in-php-with-irregular-subarray-size/
Here is array_walk way to achieve this,
function flipDiagonally($foo){
$temp = [];
array_walk($foo, function($item,$key) use(&$temp){
foreach($item as $k => $v){
$temp[$k][$key] = $v;
}
});
return $temp;
}
$bar = flipDiagonally($foo); // Mystery function
Demo.
Here's a variation of Codler/Andreas's solution that works with associative arrays. Somewhat longer but loop-less purely functional:
<?php
function transpose($array) {
$keys = array_keys($array);
return array_map(function($array) use ($keys) {
return array_combine($keys, $array);
}, array_map(null, ...array_values($array)));
}
Example:
<?php
$foo = array(
"fooA" => [ "a1", "a2", "a3"],
"fooB" => [ "b1", "b2", "b3"],
"fooC" => [ "c1", "c2", "c3"]
);
print_r( transpose( $foo ));
// Output like this:
Array (
[0] => Array (
[fooA] => a1
[fooB] => b1
[fooC] => c1
)
[1] => Array (
[fooA] => a2
[fooB] => b2
[fooC] => c2
)
[2] => Array (
[fooA] => a3
[fooB] => b3
[fooC] => c3
)
);