The usort() function is used to sort an array by its values using a user-defined comparison function. If the array you wish to sort needs to be sorted by some non-trivial criteria, you should use this function.
TRUE on success. FALSE on failure
Parameter | Description |
---|---|
array | Required. Specifies the array to sort |
myfunction | Optional. A string that define a callable comparison function. The comparison function must return an integer <, =, or > than 0 if the first argument is <, =, or > than the second argument |
Syntax
usort(array,myfunction);
Example
function my_sort_array($a,$b)
{
if ($a==$b) return 0;
return ($a<$b)?-1:1;
}
$a=array(3,2,7,5);
usort($a,"my_sort_array");
$arraylength=count($a);
for($x=0;$x<$arraylength;$x++)
{
echo $a[$x];
echo "
";
}
Output
2
3
5
7