How can I group same values in a multidimention array?
I want this
array(
array('a' => 1, 'b' => 'hello'),
array('a' => 1, 'b' => 'world'),
array('a' => 2, 'b' => 'you')
)
to become
array(
array(
array('a' => 1, 'b' => 'hello'),
array('a' => 1, 'b' => 'world')
),
array('a' => 2, 'b' => 'you')
)
function array_gather(array $orig, $equality) {
$result = array();
foreach ($orig as $elem) {
foreach ($result as &$relem) {
if ($equality($elem, reset($relem))) {
$relem[] = $elem;
continue 2;
}
}
$result[] = array($elem);
}
return $result;
}
then
array_gather($arr,
function ($a, $b) { return $a['a'] == $b['a']; }
);
This could be implemented in a more efficient matter if all your groups could be reduced to a string value (in this case they can, but if your inner arrays were something like array('a' => ArbitraryObject) they could not be).
Related
I have two arrays:
$a = ['0' => 1, '1' => 2, '2' => 3]
$b = ['0' => 4, '1' => 5, '2' => 6]
I want to create a new array like this:
[
['a' => 1, 'b' => '4'],
['a' => '2', 'b' => '5']
]
I have tried using array_merge and array_merge_recursive, but I wasn't able to get the right results.
$data = array_merge_recursive(array_values($urls), array_values($id));
You have to apply array_map() with custom function:
$newArray = array_map('combine',array_map(null, $a, $b));
function combine($n){
return array_combine(array('a','b'),$n);
}
print_r($newArray);
Output:-https://3v4l.org/okML7
Try this one
$c = array_merge($a,$b)
$d[] = array_reduce($d, 'array_merge', []);
It will merge the two array and reduce and remerge it.
You can use foreach to approach this
$a = ['0' => 1, '1' => 2, '2' => 3];
$b = ['0' => 4, '1' => 5, '2' => 6];
$res = [];
$i = 0;
$total = 2;
foreach($a as $k => $v){
$res[$i]['a'] = $v;
$res[$i]['b'] = $b[$k];
$i++;
if($i == $total) break;
}
The idea is to have an array $ab = ['a','b'] and a array from your both arrays like this $merged_array = [[1,4],[2,5],[3,6]]. Now we can combine array $ab with each element of $merged_array and that will be the result we need.
$first = ['0' => 1, '1' => 2, '2' => 3];
$second = ['0' => 4, '1' => 5, '2' => 6];
$merged_array = [];
for($i=0;$i<count($first);$i++)
{
array_push($merged_array,[$first[$i],$second[$i]]);
}
$final = [];
$ab = ['a','b'];
foreach($merged_array as $arr)
{
array_push($final,array_combine($ab, $arr));
}
print_r($final);
All earlier answers are working too hard. I see excessive iterations, iterated function calls, and counter variables.
Because there are only two arrays and the keys between the two arrays are identical, a simple foreach loop will suffice. Just push associative arrays into the result array.
Code: (Demo)
$a = ['0' => 1, '1' => 2, '2' => 3];
$b = ['0' => 4, '1' => 5, '2' => 6];
$result = [];
foreach ($a as $k => $v) {
$result[] = ['a' => $v, 'b' => $b[$k]];
}
var_export($result);
Output:
array (
0 =>
array (
'a' => 1,
'b' => 4,
),
1 =>
array (
'a' => 2,
'b' => 5,
),
2 =>
array (
'a' => 3,
'b' => 6,
),
)
I have an array that I need to get a value from within the same array that is unassigned to a variable:
return ['a' => 1, 'b'=> 'a', 'c' => 2];
So in this case I need 'b' to return the same value as 'a'. Which would be 1
Thanks for the help.
edit
I intend on running a function on b's value so the value of b is slightly different than a
return ['a' => 1, 'b'=> myFunction('a'), 'c' => 2];
You can try this way.
foreach ($array as $key => $agent) {
$array[$key]['agent_address_1'] = $agent['agent_company_1'] . ', ' .$agent['agent_address_1'];
unset($array[$key]['agent_company_1']);
}
What you want is not clear.
But i am assuming that you are trying to get the 'b' element of an array to be assigned a value similar to the value of 'a' element of that same array
If that is what you need, this will do it.
<?php
$a = array('a' => 1, 'b' => null, 'c' => 2);
$a['b'] = myFunction($a, 'a');
function myFunction($a, $b)
{
return $a[$b];
}
var_dump($a);
You can then return the array, or do what you want with it.
Maybe something like
<?php
function resolve(array $arr) {
foreach($arr as &$v) {
if ( isset($arr[$v])) {
$v = $arr[$v];
}
}
return $arr;
}
function foo() {
return resolve( ['a' => '5', 'b'=>'a', 'c' => '1'] );
}
var_export( foo() );
will do, prints
array (
'a' => '5',
'b' => '5',
'c' => '1',
)
But keep in mind that resolve( ['b'=>'a', 'a' => 'c', 'c' => '1'] ); will return
array (
'b' => 'c',
'a' => '1',
'c' => '1',
)
(you could resolve that with while( isset($arr[$v])) { instead of if ( isset($arr[$v]) ) { ...but there are most likely more elegant/performant ways to do that)
I have two arrays.
$a = array('a' => 2, 'b' => 5, 'c' => 8);
$b = array('a' => 3, 'b' => 7, 'c' => 10);
I want to merge these two arrays and get following result.
$c = array('a' => 5, 'b' => 12, 'c' => 18);
What is the easiest way to archive this?
Thanks!
As mentioned in the comments, looping through the array will do the trick.
$a = array('a' => 2, 'b' => 5, 'c' => 8);
$b = array('a' => 3, 'b' => 7, 'c' => 10);
$c = array();
foreach($a as $index => $item) {
if(isset($b[$index])) {
$new_value = $a[$index] + $b[$index];
$c[$index] = $new_value;
}
}
$c = array();
foreach ($a as $k => $v) {
if (isset($b[$k])) {
$c[$k] = $b[$k] + $v;
}
}
You need to check whether keys exist in both arrays.
You can simply use foreach as
foreach($b as $key => $value){
if(in_array($key,array_keys($a)))
$result[$key] = $a[$key]+$value;
}
You can easily do this by foreach loop, please see the example below
$c = array();
$a = array('a' => 2, 'b' => 5, 'c' => 8);
$b = array('a' => 3, 'b' => 7, 'c' => 10);
foreach ($a as $key => $value) {
$tmp_value = $a[$key] + $b[$key];
$c[$key] = $tmp_value;
}
print_r($c);
I need a custom array_replace_recursive($array, $array1) method which does what the original array_replace_recursive($array, $array1) method does except that for indexed array it should use the array in the second array and overwrite the first array recursively.
example:
$a = array (
'a' => array(1,2,3),
'b' => array('a' => 1, 'b' => 2, 'c' => 3)
);
$b = array (
'a' => array(4),
'b' => array('d' => 1, 'e' => 2, 'f' => 3)
);
$c = array_replace_recursive($a, $b);
current behaviour:
$c = array (
'a' => array(4,2,3),
'b' => array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 1, 'e' => 2, 'f' => 3)
);
desired behaviour:
$c = array (
'a' => array(4),
'b' => array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 1, 'e' => 2, 'f' => 3)
);
as you can see element 'a' is an indexed array so the element in the second array has overwritten the element in the first array. element 'b' is an associative array so it maintains the original behaviour.
Below worked for me:
<?php
/**
* This method finds all the index arrays in array2 and replaces array in array1. it checks for indexed arrays recursively only within associative arrays.
* #param $array1
* #param $array2
*/
function customMerge(&$array1, &$array2) {
foreach ($array2 as $key => $val) {
if(is_array($val)) {
if(!isAssoc($val)) {
if($array1[$key] != $val) {
$array1[$key] = $val;
}
} else {
$array1_ = &$array1[$key];
$array2_ = &$array2[$key];
customMerge($array1_, $array2_);
}
}
}
}
function isAssoc($arr)
{
return array_keys($arr) !== range(0, count($arr) - 1);
}
$a = array (
'a' => array(1,2,3),
'b' => array('a' => 1, 'b' => 2, 'c' => 3, 'g' => array(
4,5,6
))
);
$b = array (
'a' => array(4),
'b' => array('d' => 1, 'e' => 2, 'f' => 3, 'g' => array(
7
))
);
$c = array_replace_recursive($a, $b); // first apply the original method
$expected = array (
'a' => array(4),
'b' => array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 1, 'e' => 2, 'f' => 3, 'g'=> array(
7
)),
);
$d = $c; // create copy
customMerge($d, $b); // do the custom merge
echo $d == $expected;
The isAssoc() method in the first answer of this post is what your looking for:
How to check if PHP array is associative or sequential?
That method will check if the array is index and return true if it's the case.
Probably a simple one for you :
I have 2 arrays
$array1 = array(
'foo' => 5,
'bar' => 10,
'baz' => 6
);
$array2 = array(
'x' => 100,
'y' => 200,
'baz' => 30
);
I wish to get a third array by combining both the above, which should be :
$result_array = array(
'foo' => 5,
'bar' => 10,
'baz' => 36,
'x' => 100,
'y' => 200,
);
Is there any built in 'array - way' to do this, or will I have to write my own function ?
Thanks
$resultArray = $array1;
foreach($array2 as $key => $value) {
if (isset($resultArray[$key])) {
$resultArray[$key] += $value;
} else {
$resultArray[$key] = $value;
}
}
There's no built-in function for this, you'll have to write your own.
you need
$newArray = $array1;
foreach($array2 as $key => $value) {
if(array_key_exists($key, $newArray)){
$newArray[$key] += $value;
}else{
$newArray[$key] = $value;
}
}