PHP array_diff_key() Function
Example
Compare the keys of two arrays, and return the differences:
<?php
$a1=array("a"=>"red","b"=>"green","c"=>"blue");
$a2=array("a"=>"red","c"=>"blue","d"=>"pink");
$result=array_diff_key($a1,$a2);
print_r($result);
?>
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Definition and Usage
The array_diff_key() function compares the keys of two (or more) arrays, and returns the differences.
This function compares the keys of two (or more) arrays, and return an array that contains the entries from array1 that are not present in array2 or array3, etc.
Syntax
array_diff_key(array1,array2,array3...);
| Parameter | Description |
|---|---|
| array1 | Required. The array to compare from |
| array2 | Required. An array to compare against |
| array3,... | Optional. More arrays to compare against |
Technical Details
| Return Value: | Returns an array containing the entries from array1 that are not present in any of the other arrays |
|---|---|
| PHP Version: | 5.1+ |
More Examples
Example 1
Compare the keys of two indexed arrays, and return the differences:
<?php
$a1=array("red","green","blue","yellow");
$a2=array("red","green","blue");
$result=array_diff_key($a1,$a2);
print_r($result);
?>
Run example »
Example 2
Compare the keys of three arrays, and return the differences:
<?php
$a1=array("a"=>"red","b"=>"green","c"=>"blue");
$a2=array("c"=>"yellow","d"=>"black","e"=>"brown");
$a3=array("f"=>"green","c"=>"purple","g"=>"red");
$result=array_diff_key($a1,$a2,$a3);
print_r($result);
?>
Run example »
❮ PHP Array Reference
