Sorting an Array in PHP

What is PHP?

PHP is a scripting language for web development with open source and can be integrated into HTML code. PHP is known for its flexibility and large developer community. PHP is compatible with several operating systems, such as Windows, Linux, and macOS, and supports various databases, including MySQL, PostgreSQL, and SQLite.

What is an array in PHP?

In PHP, an array is a variable used to store a set of data elements identified by a unique key or index (the key can be a string or a number). PHP has two types of arrays: indexed arrays and associative arrays. PHP provides several built-in functions for manipulating arrays such as sorting, searching, checking if an element exists, splitting a string into an array, converting arrays to string or JSON, and getting the length of an array.

PHP Sort Array Examples

The following are examples of sorting a PHP array:

Sorting an array in ascending order

To sort an array in ascending order in PHP, you can use the sort() function:

<?php
$num = array(3, 1, 4, 5, 2);
sort($num);
  
print_r($num)
?>

#output: Array
#(
#    [0] => 1
#    [1] => 2
#    [2] => 3
#    [3] => 4
#    [4] => 5
#)

Sorting an array in descending order

To sort an array in descending PHP order, you can use the rsort() function:

<?php
$num = array(3, 1, 4, 5, 2);
rsort($num);
  
print_r($num)
?>

#output: Array
#(
#    [0] => 5
#    [1] => 4
#    [2] => 3
#    [3] => 2
#    [4] => 1
#)

Sorting associative arrays in ascending order

To sort associative arrays in ascending order according to their value, you can use the asort() function:

<?php
$age = array(
  'Alice' => '39', 
  'Leo' => '15', 
  'Jack' => '27'
);
asort($age);

print_r($age);
?>

#output: Array
#(
#    [Leo] => 15
#    [Jack] => 27
#    [Alice] => 39
#)

To sort associative arrays in ascending order by key, you can use the ksort() function:

<?php
$age = array(
  'Alice' => '39', 
  'Leo' => '15', 
  'Jack' => '27'
);
ksort($age);

print_r($age)
?>

#output: Array
#(
#    [Alice] => 39
#    [Jack] => 27
#    [Leo] => 15
#)

Sorting associative arrays in descending order

To sort associative arrays in descending order according to their value, you can use the arsort() function:

<?php
$age = array(
  'Alice' => '39', 
  'Leo' => '15', 
  'Jack' => '27'
);
arsort($age);

print_r($age)
?>

#output: Array
#(
#    [Alice] => 39
#    [Jack] => 27
#    [Leo] => 15
#)

To sort associative arrays in descending order by key, you can use the krsort() function:

<?php
$age = array(
  'Alice' => '39', 
  'Leo' => '15', 
  'Jack' => '27'
);
krsort($age);

print_r($age)

?>

#output: Array
#(
#    [Leo] => 15
#    [Jack] => 27
#    [Alice] => 39
#)

See also

• How do I send a GET request using PHP?
• How do I POST JSON data with PHP?