php-Arrays function-array_diff_key-calculate the difference of arrays using key name comparison_PHP tutorial

array_diff_key() function calculates the difference set of an array using key name comparison

【Function】
This function will return an array,
This array contains the values ​​of all keys that are in array1 but are not in any other parameter array.
【Scope of use】
          >=5.1.0
【Use】
array array_diff_key( array array1, array array2[,array...] )
           array1/required/array1
           array2/required/comparable array must have at least one
           array.../optional/array used for comparison
【Example】
[php]

          $arr1 = array( "key1" => "val1", "key2" => "val2" );
          $arr2 = array( "key1" => "val1", "key3" => "val2" );
          $arr3 = array( "key2" => "val2" );
            print_r( array_diff_key( $arr1, $arr2 ) );
​​​​print_r( array_diff_key( $arr1, $arr3 ) );
            print_r( array_diff_key( $arr1, $arr2, $arr3 ) );
/*
Array
(
[key2] => val2
)
Array
(
[key1] => val1
)
Array
(
)
*/

Excerpted from zuodefeng’s notes