Check if a single character is a whitespace?

Question

What is the best way to check if a single character is a whitespace?

I know how to check this through a regex.

But I am not sure if this is the best way if I onl

Answer 1

I have referenced the set of whitespace characters matched by PHP's trim function without shame (minus the null byte, I have no idea how well browsers will handle that).

if (' \t\n\r\v'.indexOf(ch) > -1) {
    // ...
}

This looks like premature optimization to me though.