TopolearnIdiomatic PHP leans on the built-in array functions instead of hand-written loops for common transformations.
PHP ships with dozens of array functions. The core trio:
array_map($fn, $array)transforms every value. With one array it keeps the keys.array_filter($array, $fn)keeps values for which$fnreturns true. Without a callback it drops falsy values. It preserves keys, so wrap it inarray_values()when you need a clean list.array_reduce($array, $fn, $initial)folds the array into one value.
Note the inconsistent argument order (callback first for array_map, second for array_filter), a famous PHP quirk. Named arguments help when in doubt.
PHP 8.4 added array_find, array_find_key, array_any and array_all, which replace many manual search loops.
Other workhorses: array_column($rows, 'email', 'id') extracts a column from rows (optionally keyed), array_combine, array_flip, array_unique, array_slice, array_merge (renumbers int keys) versus + (keeps the left side's keys), and range(1, 10).
Sorting functions sort in place and return true:
sort/rsortsort values and reindex.asort/arsortsort by value keeping keys;ksort/krsortsort by key.usort($a, fn($x, $y) => $x['age'] <=> $y['age'])sorts with a comparator. The spaceship operator<=>returns -1, 0 or 1, and arrays compare element by element, so[$a->last, $a->first] <=> [$b->last, $b->first]sorts by two fields.
PHP's sort is stable since 8.0.
Example
<?php
$people = [
['id' => 3, 'name' => 'Cy', 'age' => 41],
['id' => 1, 'name' => 'Ana', 'age' => 29],
['id' => 2, 'name' => 'Ben', 'age' => 35],
];
$names = array_map(fn($p) => $p['name'], $people);
echo implode(',', $names), "\n"; // Cy,Ana,Ben
$over30 = array_filter($people, fn($p) => $p['age'] > 30);
print_r(array_keys($over30)); // [0, 2]: keys kept
$total = array_reduce($people, fn($sum, $p) => $sum + $p['age'], 0);
echo $total, "\n"; // 105
usort($people, fn($a, $b) => $a['age'] <=> $b['age']);
echo $people[0]['name'], "\n"; // Ana
print_r(array_column($people, 'name', 'id')); // [1 => Ana, 2 => Ben, 3 => Cy]Remember
- array_map, array_filter and array_reduce cover most loops
- array_filter keeps keys; reindex with array_values
- Sort functions work in place; usort plus <=> handles custom orders
Watch out for
- Writing $sorted = sort($items); sort returns true and modifies $items in place.