PHP Tutorial - PHP krsort() Function

Definition

The krsort() function takes an array and reverse sorts it by its keys while preserving the values.

This is the opposite of the ksort().

Syntax

PHP krsort() Function has the following syntax.

bool krsort ( array &arr [, int options] )

Parameter

Parameter	Is Required	Description
arr	Required.	Array to sort
options	Optional.	How to compare the array elements/items.

Possible values for options:

Value	Description
0 = SORT_REGULAR	Default. Compare items normally without changing types)
1 = SORT_NUMERIC	Compare items numerically
2 = SORT_STRING	Compare items as strings
3 = SORT_LOCALE_STRING	Compare items as strings, based on current locale
4 = SORT_NATURAL	Compare items as strings using natural ordering
5 = SORT_FLAG_CASE	an be combined (bitwise OR) with SORT_STRING or SORT_NATURAL to sort strings case-insensitively

Note

Use the ksort() function to sort an associative array in ascending order, according to the key.

Use the arsort() function to sort an associative array in descending order, according to the value.


<?PHP
    $capitalcities['A'] = 'Z';
    $capitalcities['B'] = 'X';
    $capitalcities['C'] = 'Y';
    krsort($capitalcities);
    print_r($capitalcities);
?>

krsort() directly changes the value you pass in. The return value is either true or false, depending on whether the sorting was successful.

The code above generates the following result.

Example 2

Sort an associative array in descending order, according to the key:


<?php
$age=array("PHP"=>"5","Java"=>"7","java2s.com"=>"9");
krsort($age);
?>

The krsort() function sorts an associative array in descending order, according to the key.