Question mark and colon in JavaScript

Question

I came across the following line

hsb.s = max != 0 ? 255 * delta / max : 0;

What do the ? and : mean in this conte

Answer 1

hsb.s = max != 0 ? 255 * delta / max : 0;

? is a ternary operator. It works like an if in conjunction with the :

!= means not equals

So, the long form of this line would be

if (max != 0) { //if max is not zero
  hsb.s = 255 * delta / max;
} else {
  hsb.s = 0;
}