How to insert an item at the beginning of an array in PHP?

For an associative array you can just use merge.

$arr = array('item2', 'item3', 'item4');
$arr = array_merge(array('item1'), $arr)

There are two solutions:

1. if you have array with keys that matter to you

$new = ['RLG' => array(1,2,3)];
$array = ['s' => array(2,3), 'l' => [], 'o' => [], 'e' => []];

$arrayWithNewAddedItem = array_merge($new, $array);

2. if you have an array without any keys.

array_unshift(array, value1);

Since PHP7.4 you can use the spread opperator, very similar to JavaScript

$arr = [$item, ...$arr];

https://wiki.php.net/rfc/spread_operator_for_array

A few more examples:

// Add an item before
$arr = [$item, ...$arr];

// Add an item after
$arr = [...$arr, $item];

// Add a few more
$arr = [$item1, $item2, ...$arr, $item3];

// Multiple arrays and and items
$arr = [$item1, ...$arr1, $item2, ...$arr2, $item3];

• Note: this is only possible with int keys, not for associative arrays.
• Note2: The keys are not kept.

BREAKING Example:

$car = ['brand' => 'Audi', 'model' => 'A8'];
$engine = ['cylinder' => 6, 'displacement' => '3000cc'];

$merged = [...$car, ...$engine];

var_dump($merged);

Will result in:

[ Error ] Cannot unpack array with string keys