iwantcoding.com

🔥 Daily 👥 Rooms 🏆 Top Log in Sign up

« Previous Next »

Array Functions

By iwantcoding.com Editorial Team · Reviewed & last updated June 6, 2026 · Part of PHP Tutorial

Quick reference to the most-used array functions in PHP. Search the manual for the rest — there are about 80 in total.

Inspect

Function	Returns
`count($arr)`	Number of elements.
`array_keys($arr)` / `array_values($arr)`	Keys / values.
`array_key_exists($k, $arr)`	True even for null values.
`in_array($v, $arr, strict: true)`	Membership.
`array_search($v, $arr, strict: true)`	First key with that value, or false.
`array_is_list($arr)`	True if 0-indexed with no gaps (8.1+).

Transform

Function	Does
`array_map($fn, $arr)`	Apply fn to every value.
`array_filter($arr, $fn)`	Keep elements where fn is truthy.
`array_reduce($arr, $fn, $initial)`	Fold to a single value.
`array_column($arr, 'col')`	Pluck a column.
`array_flip($arr)`	Swap keys ↔ values.
`array_unique($arr)`	Dedup, preserve first occurrence.
`array_reverse($arr)`	Reverse order.
`array_chunk($arr, $n)`	Split into N-sized arrays.

Combine

Function	Does
`array_merge($a, $b)`	Concat; string keys overwrite.
`array_combine($k, $v)`	Pairs into dict.
`array_diff($a, $b)`	Elements in a, not in b.
`array_intersect($a, $b)`	Elements in both.

Modify

Function	Does
`array_push($arr, $v)` / `$arr[] = $v`	Append.
`array_pop($arr)`	Remove and return last.
`array_shift / array_unshift`	Front of array.
`array_splice($arr, $offset, $len, $replace)`	Remove + insert in one go.
`array_slice($arr, $offset, $len)`	Read a slice (non-destructive).

Sort

sort rsort asort arsort ksort krsort usort uksort uasort natsort — all sort in place.

Tip: Most array functions accept a callable. With arrow functions (fn($x) => ...), the resulting code reads almost like the functional equivalent in JavaScript or Python.

Lesson at a glance

Your progress through the PHP Tutorial track.

Aspect	Detail
Track	PHP Tutorial
Topic	Array Functions
Section	PHP References
Position	Lesson 75 of 90
Difficulty	Advanced
Previous	← PHP Keywords
Next	String Functions →

Example

<?php
$a = [3, 1, 4, 1, 5, 9];
echo count($a), PHP_EOL;
echo array_sum($a), PHP_EOL;
print_r(array_unique($a));
print_r(array_map(fn($n) => $n * 2, $a));
print_r(array_filter($a, fn($n) => $n > 2));

Try it Yourself »

Exercise

Count occurrences of each value.

($words)

Test yourself

📚 Study aids for Array Functions

Reading is only step one. To lock in array functions from the PHP Tutorial track, use the interactive tools iwantcoding.com ships with every lesson:

Try it live — open the in-browser PHP Tutorial editor and paste in the example above. No install required.
Drill the terms — flip through the PHP Tutorial flashcards to memorise syntax and keywords.
Prove you know it — take the PHP Tutorial boss quiz for a 10-question randomised test across the whole track.
Keep a reference — bookmark the PHP Tutorial cheatsheet for quick lookups while you code.
Continue the track — the next lesson is String Functions.

💡 Editor's tip: Learners who complete the flashcards before the boss quiz score, on average, 22% higher on the first attempt. Reading → drilling → testing → building is the order that sticks.

Discussion

Loading…

« Previous Next »

Paste broken code. AI returns a fix + explanation.

Language

Generate fresh AI questions for the current lesson.

Questions

Paste a snippet. AI scores style / best practices / errors.

Language

Web Frontend

Backend

Databases

Mobile

Cloud & DevOps

AI & Data

Cybersecurity

Tools

Specialty

Array Functions

Inspect

Transform

Combine

Modify

Sort

Example

Exercise

Test yourself

Discussion