array_diff_assoc

In this example you see the "a" => "green" pair is present in both arrays and thus it is not in the ouput from the function. Unlike this, the pair 0 => "red" is in the ouput because in the second argument "red" has key which is 1.

The above example will output:

Array
(
    [b] => brown
    [c] => blue
    [0] => red
)

    

Two values from key => value pairs are considered equal only if (string) $elem1 === (string) $elem2 . In other words a strict check takes place so the string representations must be the same.

The above example will output:

Array
(
    [0] => 0
    [1] => 1
    )