Compares the keys of two arrays and returns the intersection:
<?php$a1=array("a"=>"red","b"=>"green","c"=>"blue");$a2=array("a"=>"red", "c"=>"blue","d"=>"pink");$result=array_intersect_key($a1,$a2);print_r($result);?>The array_intersect_key() function is used to compare the key names of two (or more) arrays and return the intersection.
This function compares the keys of two (or more) arrays and returns an intersection array that includes everything in the compared array ( array1 ), as well as any other argument arrays ( array2 or array3, etc.) ) in the key name.
array_intersect_key( array1,array2,array3... )
| 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. |
| Return value: | Returns an intersection array containing all keys in the compared array ( array1 ) that are also in any other argument arrays ( array2 or array3 , etc.). |
|---|---|
| PHP version: | 5.1.0+ |
Compares the keys of two numeric arrays and returns the intersection:
<?php$a1=array("red","green","blue","yellow");$a2=array("red","green","blue");$result=array_intersect_key($a1 ,$a2);print_r($result);?>Compare the keys of three arrays and return the intersection:
<?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_intersect_key($a1,$a2,$a3);print_r($result );?>