The in operator and normal arrays

[Myron Alexander]

Hello.

I'm curious as to the reason for why the in operator only works with 
associative arrays. I am working on a program where having an in 
operator for a normal array would be useful. eg:

if ("string" in ["string1", "string2", "string3", ...]) {
    do something
}

Is there some other way to do this in the language without resorting to 
a function or class method call?

Thanks ahead,

Myron Alexander.