Using the switch(true) pattern in JavaScript

Re:Using the switch(true) pattern in JavaScript by t-writescode on Monday April 12, 2021 @03:29PM (#26783990)

I think the bigger problem you may be experiencing, if I had to guess, code structure.

If people tend to write:

   function foo(x) {
     if (x == null) {
       return null;
     }

     // do some stuff to the code


     for(a reason) {
        // do some more stuff
        if(some detailed reason) {
          return null;
     }

     // more things
     return 7;
   }

Then the shape of the code and the "pattern" of early returns gets broken.

If you read code where all of the short-circuit, early-return logic is at the start of the function, and then all of the work is done, do you still have this opinion?

E.g.

   function foo(x) {
      if(x == 1) { return null; }
      if(x == 2) { return null; }
      if(x > 7) { return null; }

      // do things with x
      return 7;
   }
?

[ Parent | on HN ]

Re:Using the switch(true) pattern in JavaScript by brundolf on Monday April 12, 2021 @03:33PM (#26784050)

The problem is definitely much worse when returns are scattered throughout the function instead of grouped at the top, but I still prefer them to be "elsed" together (or in a switch/cond/match statement or whatever). Worth noting that in Lisp - one of the classical languages where early-returning is popular - there isn't a problem because it is done as I describe:

  (cond
    (early-return-condition early-value)
    (second-early-condition early-value2)
    ...
    (t final-else-value))

The "default case" is on the same footing as the other cases. Only in procedural languages does the control-flow get confusing if you aren't careful.

[ Parent | on HN ]

Re:Using the switch(true) pattern in JavaScript by t-writescode on Monday April 12, 2021 @03:35PM (#26784078)

If you want elses everywhere, how do you protect yourself from nesting hell? I find nesting hell to be far, far, faaaar worse for readability than any of the alternatives, and will move to the early return model to escape all that nesting.

[ Parent | on HN ]

Re:Using the switch(true) pattern in JavaScript by brundolf on Monday April 12, 2021 @03:41PM (#26784157)

I dunno, I just rarely ever find myself nesting more than two or three levels of conditionals even in extreme cases. If my logic really is that complicated, it's probably a sign it needs to be broken up anyway. And if I did need that much branching, I would want to be more explicit about it, not less.

Also - at the very least - you can mimick the "flat" early-return style and just stick some else's in there and call it a day. That's my main point; less so the actual deeper nesting

[ Parent | on HN ]