PHP Function Reference

PHP array_diff_ukey() Function



The PHP array_diff_ukey() function compares keys of an array against one or more other arrays and returns all elements of the first array that are not present in any of the other arrays. This function compares keys using a user-defined comparison function.

Unlike array_diff(), this function compares keys instead of the values. Unlike array_diff_key(), this function uses a user-defined function to compare keys.

Syntax

array_diff_ukey(array, arrays, myfunction)

Parameters

array Required. Specify an array to compare from.
arrays Required. Specify one or more arrays to compare against.
myfunction Required. Specify user-defined function to compare keys. The comparison function must return an integer <, =, or > than 0 if the first argument is <, =, or > than the second argument.

Return Value

Returns an array containing all the entries from array that are not present in any of the other arrays.

Exceptions

NA.

Example:

The example below shows the usage of array_diff_ukey() function.

<?php
function MyFunc($x, $y) {
  if ($x == $y) 
    return 0;
  return ($x < $y)? -1: 1;
}

$Arr1 = array("a"=>"Red",
              "b"=>"Red",
              "c"=>"Blue",
              "d"=>"Blue",
              "e"=>"Green");
$Arr2 = array("a"=>"Red", 
              "b"=>"Blue", 
              "c"=>"Green");

//comparing Arr1 against Arr2
$Arr1_diff_Arr2 = 
    array_diff_ukey($Arr1, $Arr2, "MyFunc");

//displaying the result
print_r($Arr1_diff_Arr2);
?>

The output of the above code will be:

Array
(
    [d] => Blue
    [e] => Green
)

❮ PHP Array Reference