(PHP 4 = 4.3.0)
array_intersect_assoc() returns
an array containing all the values of
array1 that are present in all the arguments.
Note that the keys are used in the comparison unlike in
array_intersect().
In our example you see that only the pair "a" = "green" is present in both arrays
and thus is returned. The value
"red" is not returned because in
$array1 it's key is 2 while the
key of "red" in $array2 it is 1.
The two values from the key =
value pairs are considered equal only if (string) $elem1 === (string) $elem2 . In
otherwords a strict type check is executed so the string
representation must be the same.
See also array_intersect(),
array_diff() and
array_diff_assoc().