Compares the key values of two arrays and returns the difference:
<?php $a1 = array ( " a " => " red " , " b " => " green " , " c " => " blue " , " d " => " yellow " ) ; $a2 = array ( " e " => " red " , " f " => " green " , " g " => " blue " ) ; $result = array_diff ( $a1 , $a2 ) ; print_r ( $result ) ; ?>The array_diff() function is used to compare the key values of two (or more) arrays and return the difference.
This function compares the key values of two (or more) arrays and returns a difference array that includes all values in the compared array ( array1 ) but not in any other argument array ( array2 or array3, etc. ) in the key value.
array_diff( 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 a difference array that includes all keys that are in the compared array ( array1 ) but not in any other argument array ( array2 or array3 , etc.). |
|---|---|
| PHP version: | 4.0.1+ |
Compare the key values of three arrays and return the difference:
<?php $a1 = array ( " a " => " red " , " b " => " green " , " c " => " blue " , " d " => " yellow " ) ; $a2 = array ( " e " => " red " , " f " => " black " , " g " => " purple " ) ; $a3 = array ( " a " => " red " , " b " => " black " , " h " => " yellow " ) ; $result = array_diff ( $a1 , $a2 , $a3 ) ; print_r ( $result ) ; ?>