It's important to note here that PHP is converting to an integer, while JS is converting to a double. Integers don't have NaN as a concept. JS doesn't have inte

It's important to note here that PHP is converting to an integer, while JS is converting to a double. Integers don't have NaN as a concept. JS doesn't have integers, but if it did it would probably make the same kind of mistake. (This is a guess of course, but a reasonable one given the other insane conversions it does.)