PHP array_diff_ukey() function

Example

Compare the key names of two arrays (use a user-defined function to compare the key names) and return the difference:

<?phpfunction myfunction($a,$b){if ($a===$b) { return 0; } return ($a>$b)?1:-1;}$a1=array("a"=>"red","b"=>"green","c"=>"blue");$a2= array("a"=>"blue","b"= >"black","e"=>"blue");$result=array_diff_ukey($a1,$a2,"myfunction");print_r($result);?>

Definition and usage

The array_diff_ukey() function is used to compare the key names of two (or more) arrays and return the difference.

Note: This function uses a user-defined function to compare key names!

This function compares the keys of two (or more) arrays and returns a difference array that includes all the keys in the compared array ( array1 ) but not in any of the other argument arrays ( array2 or array3, etc.) ) in the key name.

grammar

 array_diff_ukey( array1,array2,array3...,myfunction );

parameter	describe
array1	Required. The first array to compare with other arrays.
array2	Required. The array to compare to the first array.
array3,...	Optional. additional array to compare with the first array
myfunction	Required. A string that defines a callable comparison function. If the first parameter <, =, > the second parameter, the corresponding comparison function must return an integer <, =, > 0.

technical details

Return value:	Returns a difference array that includes all keys that are in the compared array ( array1 ) but not in any of the other argument arrays ( array2 or array3 , etc.).
PHP version:	5.1+

More examples

Example 1

Compare the key names of the three arrays (use a user-defined function to compare the key names) and return the difference:

<?phpfunction myfunction($a,$b){if ($a===$b) { return 0; } return ($a>$b)?1:-1;}$a1=array("a"=>"red","b"=>"green","c"=>"blue");$a2= array("a"=>"black","b"=>"yellow","d"=>"brown");$a3 =array("e"=>"purple","f"=>"white","a"=>"gold");$result=array_diff_ukey($a1,$a2,$a3,"myfunction"); print_r($result);?>