Functional Array Operations
array_map()
Apply a callback to each element. Returns a new array.
array_filter()
Keep only elements where callback returns true.
array_reduce()
Reduce array to a single value using a callback.
PHP
Beginner
1 min read
array_map, filter & reduce
Example
<?php
$nums = [1, 2, 3, 4, 5];
// array_map
$doubled = array_map(fn($n) => $n * 2, $nums);
// [2, 4, 6, 8, 10]
// array_filter (keeps truthy by default)
$evens = array_filter($nums, fn($n) => $n % 2 === 0);
// [2, 4]
// array_reduce
$sum = array_reduce($nums, fn($carry, $n) => $carry + $n, 0);
// 15
// Chained with arrow functions
$result = array_reduce(
array_filter($nums, fn($n) => $n > 2),
fn($sum, $n) => $sum + $n,
0
); // 12
?>