PHP array_diff_key()Function
Examples
Compare two arrays'key names, and return the difference:
$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
array_diff_key() function is used to compare the key names of two (or more) arrayskey names, and return the difference.
This function compares the key names of two (or more) arrays, and returns a difference array that includes all the key names in the compared array (array1), but not in any other parameter array (array2orarray3etc.).
Syntax
array_diff_key(array1,array2,array3...);
| Parameter | Description |
|---|---|
| array1 | Required. The first array to compare with other arrays. |
| array2 | Required. The array to compare with the first array. |
| array3,... | Optional. Other arrays to compare with the first array. |
Technical Details
| Return value: | Returns a difference array that includes all the key names in the compared array (array1), but not in any other parameter array (array2orarray3etc.). |
|---|---|
| PHP Version: | 5.1+ |
More Examples
Example 1
Compare two numeric arrays'key names, and return the difference:
$a1=array("red","green","blue","yellow");
$a2=array("red","green","blue");
$result=array_diff_key($a1,$a2);
print_r($result);
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Example 2
Compare three arrays'key names, and return the difference:
$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 »
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