each

each(array|object &$array): array

each() no longer exists. It was deprecated in PHP 7.2 and removed in PHP 8.0, so calling it today throws Error: Call to undefined function each(). This page exists because a lot of pre-PHP 7 code still uses it and you need to know what it did and what to write instead.

It returned a four-element array describing the element the array's internal pointer was on — keys 0 and key held the key, keys 1 and value held the value — and moved the pointer forward one step. Once the pointer ran off the end it returned false, which is what terminated the classic while (list($k, $v) = each($arr)) loop.

What to use instead

• To walk a whole array: foreach ($arr as $k => $v). This replaces virtually every real use, and it is faster because it iterates a copy and never touches the internal pointer.
• To step one element at a time under your own control: reset() first, then key() and current() to read, and next() to advance.

It was removed precisely because that internal pointer was a language-level obstacle, and because a stale pointer from an earlier loop silently made the next one start in the middle.

<?php
// Legacy PHP 5 style - this FATALS on PHP 8.
$stock = ['apples' => 3, 'pears' => 0];

reset($stock);
while (list($item, $qty) = each($stock)) {
    echo "$item: $qty\n";
}

// The PHP 8 replacement:
foreach ($stock as $item => $qty) {
    echo "$item: $qty\n";
}

<?php
$stock = ['apples' => 3, 'pears' => 0, 'plums' => 12];

foreach ($stock as $item => $qty) {
    echo str_pad($item, 8), $qty, "\n";
}

echo "total: ", array_sum($stock), "\n";

<?php
$colors = ['red', 'green', 'blue'];

reset($colors);
while (($k = key($colors)) !== null) {
    echo $k, ' => ', current($colors), "\n";
    next($colors);
}

<?php
var_dump(function_exists('each'));

if (!function_exists('each')) {
    echo "each() was removed in PHP 8.0 - rewrite the loop as foreach\n";
}

echo 'running on PHP ', PHP_VERSION, "\n";