array_push() with key value pair

To add key-value pairs to an array in PHP, the most reliable method is using the direct assignment syntax: $array['key'] = 'value'.

Adding key-value pairs to an array in PHP

<?php

$array = array('apple' => 'red', 'banana' => 'yellow');

$array['mango'] = 'orange';
$array['pear'] = 'green';

print_r($array);

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Output:

Array ( [apple] => red [banana] => yellow [mango] => orange [pear] => green )

Note that array_push() is designed for appending sequential values and cannot merge key-value pairs. When you pass an associative array to array_push(), PHP treats it as a single element and assigns it a numeric key, which nests the array instead of adding its pairs to the target array:

How array_push() handles associative arrays

<?php

$array = array('apple' => 'red', 'banana' => 'yellow');

array_push($array, array('mango' => 'orange', 'pear' => 'green'));

print_r($array);

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Output:

Array ( [apple] => red [banana] => yellow [0] => Array ( [mango] => orange [pear] => green ) )

If you only need to append values to the end of an array, array_push() works as expected:

Using array_push() for sequential values

<?php

$array = array('apple', 'banana');

array_push($array, 'mango', 'pear');

print_r($array);

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Output:

Array ( [0] => apple [1] => banana [2] => mango [3] => pear )

For merging existing associative arrays, consider array_merge() or the + operator instead.

Merging associative arrays with array_merge()

<?php

$array1 = array('apple' => 'red', 'banana' => 'yellow');
$array2 = array('mango' => 'orange', 'pear' => 'green');

$merged = array_merge($array1, $array2);
print_r($merged);

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Output:

Array ( [apple] => red [banana] => yellow [mango] => orange [pear] => green )