Whats a better way to do these nested if statements?

Question

I forgot to mention using the result of bar to calculate foo's value in the question I asked here.

The function bar only needs to be called if conditionA is true. But when the result of bar (resultBar) is falsy, I want to run the code that would have run if conditionA had been false. Is there a more concise way of approaching this without duplication?

var scale = 1;
if(settings.doUseOutlines) {
    var typefaceSize = getTypefaceSize(typefaceComp);
    if(typefaceSize) {
        scale = parseFloat(settings.fontScale) / typefaceSize[1];
    } else {
        scale = parseFloat(settings.fontScale) / typefaceComp.height; // duplicated
    }
} else {
    scale = parseFloat(settings.fontScale) / typefaceComp.height;
}

Answer 1

You can use the short circuit feature of the && operator to only call the function if the first condition is true, and the fact that the value of the assignment is the assigned value so that you can do the assignment and check it's value in one statement:

var scale, typefaceSize;
if (settings.doUseOutlines && (typefaceSize = getTypefaceSize(typefaceComp))) {
  scale = parseFloat(settings.fontScale) / typefaceSize[1];
} else {
  scale = parseFloat(settings.fontScale) / typefaceComp.height;
}

This is of course a bit of a convoluted way to write it. The original code is still clearer in some ways, so you get to choose between simplicity and avoiding repetition.

Choosing the height depending on the conditions and thus breaking out most of the calculation (based on Winston Ewerts answer), makes it even less repetetive:

var height = typefaceComp.height, typefaceSize;
if (settings.doUseOutlines && (typefaceSize = getTypefaceSize(typefaceComp))) {
  height = typefaceSize[1];
}
var scale = parseFloat(settings.fontScale) / height;

Answer 2

var height = typefaceComp.height;
if(settings.doUseOutlines) {
    var typefaceSize = getTypefaceSize(typefaceComp);
    if(typefaceSize) {
        height = typefaceSize[1];
    } 
} 

var scale = parseFloat(settings.fontScale) / height;