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PHP: uksort() function

PHP: Sort an array by keys using a user-defined comparison function

The uksort() function is used to sort an array by the element keys 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.

Note: If two members compare as equal, their relative order in the sorted array is undefined.

Version:

(PHP 4 and above)

Syntax:

uksort(array_name, user_defined_function)

Parameters:

Name Description Required /
Optional		 Type
array_name The input array. Required Array
user_defined_function User supplied function. Required
-

Return value

TRUE on success or FALSE on failure.

Value Type : Boolean.

Example:

<?php
function my_sort($x, $y)
{
if ($x == $y) return 0;
return ($x > $y) ? -1 : 1;
}
$people = array("10" => "javascript",
"20" => "php", "60" => "vbscript",
"40" => "jsp");
uksort($people, "my_sort");
print_r ($people);
?>

Output:

Array ([60] => vbscript [40] => jsp [20] => php [10] => javascript )

Pictorial Presentation:

php function reference: uksort() function

View the example in the browser

Practice here online:

See also

PHP Function Reference

Previous: uasort
Next: usort



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PHP: Tips of the Day

Filters the collection using the given callback

Example:

<?php
function tips_reject($items, $func)
{
  return array_values(array_diff($items, array_filter($items, $func)));
}

print_r(tips_reject(['Apple', 'Pear', 'Kiwi', 'Banana'], function ($item) {
  return strlen($item) > 4;
}));
?>

Output:

Array
(
    [0] => Pear
    [1] => Kiwi
)