New Array Search Functions in PHP 8.4: array_find, array_find_key, and array_find_index

PHP 8.4 brings a set of new array‑search functions that greatly enhance the way developers work with arrays. The three functions— array_find(), array_find_key(), and array_find_index() —allow you to search an array using a user‑defined callback and return the first matching element, its key, or its numeric index.

array_find()

This function iterates over an array and returns the first element that satisfies the condition defined in the callback. Its signature is:

array_find(array $array, callable $callback): mixed

The $array parameter is the array to search, and $callback should return true for the desired element. If a matching element is found, its value is returned; otherwise null, false, or another implementation‑specific value may be returned.

Example:

$numbers = [1, 2, 3, 4, 5];
$result = array_find($numbers, function($value) {
    return $value > 3;
});

echo $result; // outputs: 4

array_find_key()

This function searches an array and returns the key of the first element that meets the callback condition. Its signature is:

array_find_key(array $array, callable $callback): int|string|null

If a matching element is found, the key (integer or string) is returned; otherwise null is returned. The callback must return a boolean.

Example:

$users = [
    'john' => ['age' => 25],
    'jane' => ['age' => 30],
    'doe'  => ['age' => 35],
];
$key = array_find_key($users, function($user) {
    return $user['age'] > 28;
});

echo $key; // outputs: jane

array_find_index()

This function is similar to array_find_key() but returns the numeric index of the first element that satisfies the callback. Its signature is:

array_find_index(array $array, callable $callback): int|null

If a matching element is found, its integer index is returned; otherwise null is returned.

Example:

$colors = ['red', 'green', 'blue', 'yellow'];
$index = array_find_index($colors, function($color) {
    return $color === 'blue';
});

echo $index; // outputs: 2

These new functions simplify custom array searches, make code more expressive, and improve maintainability in PHP web development.