Question:

When giving PHP in_array an array of values I want to search for, it does not work. Although the documentation specifies that you can give a <em>mixed</em> needle.

So basically I want to test for the presence of multiple terms as the value of an array - is there a reason this is not working, and can anyone suggest another way of doing this?

mixed doesn't mean more than one needle, it refers to types. It's documentation talk for more than one possible type.

For something like searching an array $haystack for multiple $needles that are all strings or numbers, you can use array_intersect($array1, $array2, ...)

<a href="http://php.net/manual/en/function.array-intersect.php" rel="nofollow">http://php.net/manual/en/function.array-intersect.php</a>

It should work for mixed types also.

When the documentation says mixed it means it can accept multiple types, e.g. int, float, string. Though the docs should say exactly which types are valid.