How to Sort Numeric Array in PHP?

Given a numeric array, the task is to sort the numeric array using PHP. There are various built-in functions to sort arrays in different ways.

Below are the approaches to sort numeric arrays in PHP:

Using sort() Function

The sort() function sorts an array in ascending order. It sorts the values without maintaining the original keys.

Example: This example shows the implementation of the above-explained approach.

<?php

// Create an Array
$arr = [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5];

// Function to sort array
sort($arr);

print_r($arr);

?>

Output

Array
(
    [0] => 1
    [1] => 1
    [2] => 2
    [3] => 3
    [4] => 3
    [5] => 4
    [6] => 5
    [7] => 5
    [8] => 5
    [9] => 6
    [10] => 9
)

Using rsort() Function

The rsort() function sorts an array in descending order. Like sort(), it does not maintain the original keys.

Example: This example shows the implementation of the above-explained approach.

<?php

// Create an Array
$arr = [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5];

// Function to sort array in
// descending order
rsort($arr);

print_r($arr);

?>

Array
(
    [0] => 9
    [1] => 6
    [2] => 5
    [3] => 5
    [4] => 5
    [5] => 4
    [6] => 3
    [7] => 3
    [8] => 2
    [9] => 1
    [10] => 1
)

Using asort() Function

The asort() function sorts an array in ascending order while maintaining the original keys.

Example: This example shows the implementation of the above-explained approach.

<?php

// Create an Array
$arr = [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5];

// Function to sort array in
// ascending order without 
// changing the key
asort($arr);

print_r($arr);

?>

Output

Array
(
    [1] => 1
    [3] => 1
    [6] => 2
    [0] => 3
    [9] => 3
    [2] => 4
    [4] => 5
    [8] => 5
    [10] => 5
    [7] => 6
    [5] => 9
)

Using arsort() Function

The arsort() function sorts an array in descending order while maintaining the original keys.

Example: This example shows the implementation of the above-explained approach.

<?php

// Create an Array
$arr = [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5];

// Function to sort array in
// descending order without 
// changing the key
arsort($arr);

print_r($arr);

?>

Array
(
    [5] => 9
    [7] => 6
    [4] => 5
    [8] => 5
    [10] => 5
    [2] => 4
    [0] => 3
    [9] => 3
    [6] => 2
    [1] => 1
    [3] => 1
)

Using usort() Function

The usort() function sorts an array by values using a user-defined comparison function. This is useful when you need a custom sorting logic.

Example: This example shows the implementation of the above-explained approach.

<?php

// Create an Array
$arr = [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5];

// Compare function
function customCompare($a, $b) {
    return $a - $b;
}

usort($arr, "customCompare");

print_r($arr);

?>

Output

Array
(
    [0] => 1
    [1] => 1
    [2] => 2
    [3] => 3
    [4] => 3
    [5] => 4
    [6] => 5
    [7] => 5
    [8] => 5
    [9] => 6
    [10] => 9
)

Using natsort()

The natsort() function sorts an array using a natural order algorithm.

Example: This example shows the implementation of the above-explained approach.

<?php
$array = array(3, 2, 9, 7, 5, 1, 4);
natsort($array);

print_r($array);
?>

Array
(
    [5] => 1
    [1] => 2
    [0] => 3
    [6] => 4
    [4] => 5
    [3] => 7
    [2] => 9
)