'Zip multiple arrays in PHP based on their identical keys and not their indices or their positions in array

I have two arrays:

$a = ['one'=>1,'two'=> 2,'three'=> 3,'four'=> 4,'five'=> 5, 'six' => 6];
$b = ['one'=>'uno', 'three'=>'tres','two'=> 'dos', 'four'=>'cuatro', 'five'=>'cinco'];

note that in $b Array 'three' and 'two' keys are not in same order as $a. also 'six' key is not available in $b Array.

I want this result as output:

Array
(
    [0] => Array
        (
            [0] => 1
            [1] => uno
        )

    [1] => Array
        (
            [0] => 2
            [1] => dos
        )

    [2] => Array
        (
            [0] => 3
            [1] => tres
        )

    [3] => Array
        (
            [0] => 4
            [1] => cuatro
        )

    [4] => Array
        (
            [0] => 5
            [1] => cinco
        )

)

I tried to use array_map but it don't detect keys and just zip them based of their indices:

$d = array_map(null, $a, $b);
phparrays


Solution 1:[1]

Can't you just use ksort(). Then, create a new array using `foreach'?

Solution 2:[2]

An example using foreach

<?php

$a = ['one' => 1, 'two' => 2, 'three' => 3, 'four' => 4, 'five' => 5];
$b = ['one' => 'uno', 'three' => 'tres', 'two' => 'dos', 'four' => 'cuatro', 'five' => 'cinco'];

$output = [];

foreach ($a as $key => $value) {
    $output[] = [$value,  $b[$key]];
}

print_r($output);

Solution 3:[3]

modified ikhvjs answer (when keys in both arrays are not same as each others):

$a = ['one' => 1, 'two' => 2, 'four' => 4, 'five' => 5, 'six' => 6];
$b = ['one' => 'uno', 'three' => 'tres', 'two' => 'dos', 'four' => 'cuatro', 'five' => 'cinco'];    
$r=array_intersect_key($a,$b);
$output = [];    
foreach ($r as $key => $value) {
    $output[] = [$value,  $b[$key]];
}
echo "<pre>";
print_r($output);
echo "</pre>";

Solution 4:[4]

I must say @ikhvjs's answer is the closest to perfect, but the $b array doesn't have a value with the key six. To accommodate the possibility of elements in $b not relating to elements in $a, use the null coalescing operator to fallback to a null value.

As for the mentioning of ksort(), this will do nothing to accommodate the fact that the input arrays have different lengths / keys.

The use of array_intersect_key() will result in $a values being omitted where not related to an element in $b.

If $a is not a reliable "master" array (with all possible keys), then you will need to loop a temporary array formed by merging the two arrays and implement the null coalescing operator on both values to be pushed into the result array.

Code: (Demo) (Demo of null coalescing on both values)

$a = [
    'one' => 1,
    'two' => 2,
    'three' => 3,
    'four' => 4,
    'five' => 5,
    'six' => 6
];
$b = [
    'one' => 'uno',
    'three' => 'tres',
    'two' => 'dos',
    'four' => 'cuatro',
    'five' => 'cinco'
];

$result = [];
foreach ($a as $k => $v) {
    $result[] = [$v, $b[$k] ?? null];
}
var_export($result);

Output:

array (
  0 => 
  array (
    0 => 1,
    1 => 'uno',
  ),
  1 => 
  array (
    0 => 2,
    1 => 'dos',
  ),
  2 => 
  array (
    0 => 3,
    1 => 'tres',
  ),
  3 => 
  array (
    0 => 4,
    1 => 'cuatro',
  ),
  4 => 
  array (
    0 => 5,
    1 => 'cinco',
  ),
  5 => 
  array (
    0 => 6,
    1 => NULL,
  ),
)

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 ?ukasz Socha
Solution 2 ikhvjs
Solution 3
Solution 4 mickmackusa

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