PHP Array Functions – Master Built-in Tools for Array Manipulation

Explore the most essential and powerful array functions in PHP to simplify data handling, sorting, filtering, and transformation.

Introduction – Why Use Array Functions in PHP?

PHP provides a rich set of built-in array functions to help you manage, transform, and analyze array data easily. Whether you’re filtering user input, merging datasets, or sorting values, these functions can reduce complex logic into a single line of code.

In this guide, you’ll learn:

• The most commonly used PHP array functions
• Syntax and examples for each function
• Real-world use cases
• Best practices for effective array handling

1. Array Creation & Inspection

count() – Count Elements

$colors = ['red', 'green', 'blue'];
echo count($colors); // 3

is_array() – Check If a Variable is an Array

$data = ["a", "b"];
echo is_array($data) ? "Yes" : "No"; // Yes

2. Add, Remove, Modify Elements

array_push() – Add One or More Items

$fruits = ["apple"];
array_push($fruits, "banana", "cherry");

array_pop() – Remove the Last Item

array_pop($fruits); // Removes "cherry"

⬅️ array_unshift() – Add to Beginning

array_unshift($fruits, "mango");

array_shift() – Remove First Element

array_shift($fruits); // Removes "mango"

3. Search and Filter

in_array() – Check If Value Exists

in_array("banana", $fruits); // true

array_key_exists() – Check If Key Exists

$user = ["name" => "John"];
array_key_exists("name", $user); // true

array_filter() – Remove Unwanted Values

$nums = [0, 1, 2, null, false];
$clean = array_filter($nums); // Removes falsy values

4. Extract Keys & Values

array_keys() – Get All Keys

array_keys($user); // ["name"]

array_values() – Get All Values

array_values($user); // ["John"]

5. Sorting Arrays

sort() – Sort Indexed Array by Values (Ascending)

sort($colors); // ["blue", "green", "red"]

rsort() – Descending Sort

rsort($colors);

asort() – Sort Associative Array by Values

asort($user);

ksort() – Sort Associative Array by Keys

ksort($user);

6. Merge, Slice, Chunk

array_merge() – Merge Two or More Arrays

$a = [1, 2]; $b = [3, 4];
$c = array_merge($a, $b); // [1, 2, 3, 4]

array_slice() – Extract a Portion of an Array

array_slice($a, 1); // [2]

array_chunk() – Split Array into Chunks

array_chunk($a, 1); // [[1], [2]]

7. Transform Arrays

array_map() – Apply Function to Each Element

$squared = array_map(fn($n) => $n * $n, [1, 2, 3]); // [1, 4, 9]

array_reduce() – Reduce to a Single Value

$sum = array_reduce([1, 2, 3], fn($carry, $item) => $carry + $item); // 6

Best Practices

• Use array_map and array_filter for cleaner functional logic
• Use array_merge instead of + for combining arrays safely
• Use array_key_exists() for key checking (not isset() when value can be null)
• Avoid modifying an array while looping through it

Summary – Recap & Next Steps

PHP array functions simplify the way you handle data structures in your application. They turn repetitive tasks into one-liners, making your code shorter, faster, and more readable.

Key Takeaways:

• Use array_* functions to manipulate, transform, and analyze arrays
• Combine map, filter, and reduce for expressive, functional logic
• Know when to sort, merge, or slice for specific scenarios

Real-World Use Cases:
Filtering user input, processing form data, aggregating reports, structuring JSON for APIs.

Frequently Asked Questions (FAQs)

Which function adds elements to the end of an array?
array_push().

How do I remove the first element?
Use array_shift().

What’s the difference between array_merge() and + operator?
array_merge() appends values; + preserves keys and skips duplicates.

Can I filter out empty values?
Yes, using array_filter($arr) without a callback removes falsy values.

How do I get the total of an array of numbers?
Use array_reduce().