Definition and Usage
The array_diff_key() function compares two or more arrays, and returns an array with the keys and values from the first array, only if the key is not present in any of the other arrays.Syntax
array_diff_key(array1,array2,array3...)
| Parameter | Description |
|---|---|
| array1 | Required. The first array is the array that the others will be compared with |
| array2 | Required. An array to be compared with the first array |
| array3 | Optional. An array to be compared with the first array |
Tips and Notes
Tip: You can compare the first array with one array, or as many as you like.Note: Only the key is used in the comparison.
Example
<?php
$a1=array(0=>"Cat",1=>"Dog",2=>"Horse");
$a2=array(2=>"Bird",3=>"Rat",4=>"Fish");
$a3=array(5=>"Horse",6=>"Dog",7=>"Bird");
print_r(array_diff_key($a1,$a2,$a3));
?>
$a1=array(0=>"Cat",1=>"Dog",2=>"Horse");
$a2=array(2=>"Bird",3=>"Rat",4=>"Fish");
$a3=array(5=>"Horse",6=>"Dog",7=>"Bird");
print_r(array_diff_key($a1,$a2,$a3));
?>
OUTPUT :
Array ( [0] => Cat [1] => Dog )