I am trying to replace an array key (= single letter) with a word. I have a associative array and a $mapKeyArray with the replacement words
$inputArray = ['P' => 72,'T' => 0,'U' => 1,'E' => 0];
function cb_replaceWords($a) {
$mapKeyArray = array('P' => 'Pink', 'T' => 'Top', 'U' => 'Union', 'E' => 'EX');
foreach($a as $key) {
// $a[$key] = $mapKeyArray[$key];
$a[$key];
}
return $a;
}
$outputArray = array_map("cb_replaceWords", $inputArray);
Modify your function as:
function cb_replaceWords($a) {
$result = [];
$mapKeyArray = array('P' => 'Pink', 'T' => 'Top', 'U' => 'Union', 'E' => 'EX');
foreach($a as $key => $value) {
$result[$mapKeyArray[$key]] = $value;
}
return $result;
}
// and there's no need to use array_map
$outputArray = cb_replaceWords($inputArray);
In case your arrays have the same order of keys you can replace all this with array_combine:
$outputArray = array_combine($mapKeyArray, $inputArray);
I am trying to sort the following arrays.
Array(s)
$fruits = array(
'mango',
'mango red',
'mango yellow',
'orange',
'banana',
'apple',
'apple red',
'apple green',
);
What I have done:
$data = array_flip( $fruits ); // flip array
$data = array_fill_keys( array_keys( array_flip( $data ) ), 'array(),' ); // fill array value: "array(),"
print_r( $data );
I want this result:
$fruits = array(
'mango' => array(
'red' => array(),
'yellow' => array(),
),
'orange' => array(),
'banana' => array(),
'apple' => array(
'red' => array(),
'green' => array(),
),
);
Does anybody know how to do this?
Hope you can understand the question. Thank you in advance.
Loop through the array, and split the string. Then recursively create nested arrays.
$result = array();
foreach ($fruits as $f) {
$f_array = explode(' ', $f);
$start = &$result;
foreach ($f_array as $word) {
if (!isset($start[$word])) {
$start[$word] = array();
}
$start = &$start[$word];
}
}
var_dump($result);
DEMO
Use the following approach(for your current array):
$result = [];
foreach ($fruits as $fruit) {
$parts = explode(' ', $fruit);
if (count($parts) == 1) {
$result[$fruit] = [];
} elseif (isset($result[$parts[0]])) {
$result[$parts[0]][$parts[1]] = [];
}
}
print_r($result);
I have an array that looks something like this:
$array = array(
array('Field1' => 'red', 'Field2' => 'green', 'Field3' => 'blue'),
array('Field1' => 'pink', 'Field2' => 'pinkish', 'Field3' => 'barbiecolor'),
array('Field1' => 'red', 'Field2' => 'blue', ' Field3' => 'orange')
);
And I want to check this by the given values:
$searchBy = array('Field1' => 'red', 'Field2' => 'blue');
What I want to achieve, is to return the parent array that has all associative key & value pairs matched. I've tried in_array() but it doesn't work..
array_filter may be better for this:
$matches = array_filter($array,function($a) use ($searchBy) {
foreach($searchBy as $k=>$v) {
if( $a[$k] != $v) return false;
}
return true;
});
You can try:
$find = array_filter($array, function ($a) use($searchBy) {
return array_intersect_assoc($searchBy, $a) == $searchBy;
});
See Live Demo
Old School Version
$find = find($searchBy, $array);
print_r($find);
// Function used
function find($needle, $haystack) {
$r = array();
foreach ( $haystack as $k => $a ) {
array_intersect_assoc($needle, $a) == $needle and $r[$k] = $a;
}
return $r;
}
Old School Demo
How can I search for a key in an array that contains more arrays.
For example I would like to search for "key" in "arr" and return this:
arr["some_inner_array"]["another_array_possible"][key"]
array_key_exists can tell me if it exists, but of course what I really need in the value...
I hope my question is clear...
EDIT:
based on the answer below, I managed to do a recursive function for that:
function look_in_array ( $array, $key ) {
if ( isset($array[$key]) )
return $array[$key];
foreach ($array as $item) {
if (is_array($item)) {
$value = look_in_array ($item,$key);
if ($value)
return $value;
}
}
}
This function should work:
function array_key_exists_recursive($searchKey, $array)
{
$result = false;
foreach($array as $key => $value)
{
if(is_array($array[$key]))
{
$result = array_key_exists_recursive($searchKey, $array[$key]);
}
else if(array_key_exists($searchKey, $array))
{
$result = $array[$searchKey];
}
if($result)
break;
}
return $result;
}
Exmaple:
$array = array( "a" => array("b" => "1", "c" => "2") );
var_dump(array_key_exists_recursive("c", $array)); //Result: 2
You could just ask this:
isset(arr["some_inner_array"]["another_array_possible"]["key"])
Would this work for you? Otherwise maybe explaning a bit better about what you're trying to accomplish would help us help you :)
You need to iterate over all elements in the first arrays and then use array_key_exists():
foreach($arr as $inner1) {
foreach($inner1 as $inner2) {
if array_key_exists($inner2, $key) {
echo $inner2[$key];
break 2; // if you only want the first match
}
}
}
Try this:
/**
* #param $path array containing path
* #param $array search array
* #return element matching path or null
*/
function arr_search($path, &$array){
$tmp = &$array;
for($i = 0; $i < count($path); $i++){
if(!isset($tmp[$path[$i]])) return null;
$tmp = &$tmp[$path[$i]];
}
return $tmp;
}
$arr = array(
'a' => array(
'b' => array(
'c' => 'abc',
),
'd' => array('ad'),
),
10 => array(100, 200, 300),
);
var_dump(arr_search(array('a', 'b', 'c'), $arr));
var_dump(arr_search(array('a', 'd'), $arr));
var_dump(arr_search(array(10, 100), $arr));
var_dump(arr_search(array(10, 1), $arr));
// EDIT previous example was wrong, so here is new one :)
function arr_search($key, $array){
$values = array();
if(array_key_exists($key, $array)) $values[] = $array[$key];
$stack = array_values($array);
while($tmp = array_pop($stack)){
if(is_array($tmp)){
foreach($tmp as &$v){
array_push($stack, $v);
}
if(array_key_exists($key, $tmp)){
$values[] = $tmp[$key];
}
}
}
return $values;
}
$arr = array(
'a' => array(
'b' => array(
'c' => 'abc',
),
'd' => array('ad'),
),
'e' => array(
'a' => array(
'b' => 'abc',
),
'b' => array('xyz'),
),
10 => array(100, 200, 300),
);
var_dump(arr_search('b', $arr));
var_dump(arr_search(0, $arr));
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
)
);