Re: FILTER_VALIDATE_INT - newbie question

> Also, I think you're getting confused over the zero with exactly what > you are asking PHP to do. filter_var() returns true if the filter > matches. If the 0 match is returned as a false, then filter_var() will filter_var() actually returns the filtered data if the filter matches, and FALSE if it doesn't. That's the whole point of the filter_XXX functions; to pass a tainted value through a filter and get a clean, "safe" value out the other end: $tainted = get_user_input(); $clean = filter_var($tainted, [FILTER_CONSTANT]); // now use $clean and never touch $tainted again From the original code above, it looks like the OP was misunderstanding the use of filter_var() and expecting it to return a boolean. Ben