It's because it _is_ working javascript. It's just obfuscated, taking advantage of the quirks of javascript's implicit type casting to represent expressions in

It's because it _is_ working javascript. It's just obfuscated, taking advantage of the quirks of javascript's implicit type casting to represent expressions in odd ways. Look at the "basics" section of the page to get an idea of how it works on a small scale. Brainfuck is an unrelated, separate programming language.