The array() function in PHP is used to create an array. Arrays in PHP are versatile data structures that can hold multiple values under a single variable name. This function allows you to define both indexed and associative arrays.

Syntax:

array(mixed $value1, mixed $value2, ..., mixed $valueN)

Parameters:

• mixed $value1, $value2, ..., $valueN: A variable number of values that you want to include in the array. You can pass as many values as you like, including other arrays.

Return Value:

• The function returns an array containing the values passed as arguments.

Example 1: Creating an Indexed Array

An indexed array uses numeric keys to store values. Here's how you can create one:

<?php
$fruits = array("Apple", "Banana", "Cherry");

// Output the array
print_r($fruits);
?>

Output:

Array
(
    [0] => Apple
    [1] => Banana
    [2] => Cherry
)

Example 2: Creating an Associative Array

An associative array uses named keys that you assign to them. This allows you to access values using those keys.

<?php
$person = array(
    "name" => "John",
    "age" => 30,
    "city" => "New York"
);

// Output the array
print_r($person);
?>

Output:

Array
(
    [name] => John
    [age] => 30
    [city] => New York
)

Example 3: Creating a Multi-Dimensional Array

You can also create arrays within arrays, known as multi-dimensional arrays. This is useful for storing more complex data structures.

<?php
$students = array(
    array("name" => "Alice", "age" => 22),
    array("name" => "Bob", "age" => 24),
    array("name" => "Charlie", "age" => 23)
);

// Output the array
print_r($students);
?>

Output:

Array
(
    [0] => Array
        (
            [name] => Alice
            [age] => 22
        )

    [1] => Array
        (
            [name] => Bob
            [age] => 24
        )

    [2] => Array
        (
            [name] => Charlie
            [age] => 23
        )
)

Example 4: Using array() to Create an Empty Array

You can also create an empty array and populate it later.

<?php
$empty_array = array(); // Create an empty array

// Add elements to the array
$empty_array[] = "First Item";
$empty_array[] = "Second Item";

// Output the array
print_r($empty_array);
?>

Output:

Array
(
    [0] => First Item
    [1] => Second Item
)

Example 5: Nested Arrays

You can create nested arrays, allowing for even more complex data structures.

<?php
$library = array(
    "fiction" => array("The Great Gatsby", "1984"),
    "non_fiction" => array("Sapiens", "Educated")
);

// Output the array
print_r($library);
?>

Output:

Array
(
    [fiction] => Array
        (
            [0] => The Great Gatsby
            [1] => 1984
        )

    [non_fiction] => Array
        (
            [0] => Sapiens
            [1] => Educated
        )
)

Summary:

• The array() function is a fundamental method in PHP for creating arrays, which can be indexed or associative.
• You can store multiple types of data within arrays, including other arrays, allowing for complex data structures.
• Arrays are commonly used for storing lists of items, configuration options, and more, making them an essential part of PHP programming.

Note:

As of PHP 5.4, you can also use the short array syntax with square brackets to create arrays, which is often preferred for its simplicity:

$fruits = ["Apple", "Banana", "Cherry"];