A somewhat painful triple-nested ternary operator

Question

I went looking through Raphael.js\'s source code to find out how he converted RGB values to HSB. I found out the function he did it in and I was in the process

Answer 1

The same logic can be written in a simpler way:

var H

if (C == 0)
    H = null;
else if (V == r)
    H = (g - b) / C;
else if (V == g)
    H = (b - r) / C + 2;
else
    H = (r - g) / C + 4;

It's possible to omit the curly braces because there's a single statement in each condition. And given that the conditions are mutually exclusive, using else if is much clearer than nesting ifs.

Answer 2

As mentioned in MDN Docs:

function example(…) {
    return condition1 ? value1
         : condition2 ? value2
         : condition3 ? value3
         : value4;
}

// Equivalent to:

function example(…) {
    if (condition1) { return value1; }
    else if (condition2) { return value2; }
    else if (condition3) { return value3; }
    else { return value4; }
}

Answer 3

I think you can have this to avoid the deep nesting:

var H

if(C == 0){
    H = null;
}
else if(V == r){
    H = (g - b) / C;
}
else if (V == g){
    H = (b - r) / C + 2;
}
else {
    H = (r - g) / C + 4;
}