How to sort an associative array by key in PHP

Topic: PHP / MySQLPrev|Next

Answer: Use the PHP ksort() and krsort() function

The PHP ksort() and krsort() functions can be used for sorting an array by key. The following section will show you how these functions basically work.

Sorting Associative Arrays in Ascending Order

You can use the ksort() function for sorting an associative array by key alphabetically in the ascending order, while maintaining the relationship between key and data.

<?php
$fruits = array("b"=>"banana", "a"=>"apple", "d"=>"dog", "c"=>"cat");
 
// Sorting the array by key
ksort($fruits);
print_r($fruits);
?>

Sorting Associative Arrays in Descending Order

You can use the krsort() function for sorting an associative array by key alphabetically in the descending order, while maintaining the relationship between key and data.

<?php
$fruits = array("b"=>"banana", "a"=>"apple", "d"=>"dog", "c"=>"cat");
 
// Sorting the array by key
krsort($fruits);
print_r($fruits);
?>

Related FAQ

Here are some more FAQ related to this topic:

• How to sort an associative array by value in PHP
• How to get all the keys of an associative array in PHP
• How to get all the values from an associative array in PHP