PHP - Array usort() Function
The PHP Array usort() function is used to sort an indexed array using user-defined comparison function. The function must return an integer to work correctly and it should take only two parameters to compare.
Syntax
usort(array, myfunction)
Parameters
array |
Required. Specify the indexed array to sort |
myfunction |
Required. Specify user-defined function to compare keys. The function must return an integer to work correctly and it should take only two parameters to compare. |
Return Value
Returns TRUE on success and False in failure.
Exceptions
NA.
Example:
In the below example, usort() function is used to sort an indexed array called MyArray using user-defined function MyFunction.
<?php function MyFunction($x, $y) { if ($x == $y) return 0; return ($x < $y)? -1: 1; } $MyArray = array("Marry", "John", "Jo", "Kim", "Adam"); usort($MyArray, "MyFunction"); print_r($MyArray); ?>
The output of the above code will be:
Array ( [0] => Adam [1] => Jo [2] => John [3] => Kim [4] => Marry )
❮ PHP Array functions