What is the best way to replace or substitute if..else if..else trees in programs?

Question

This question is motivated by something I\'ve lately started to see a bit too often, the if..else if..else structure. While it\'s simple and has its uses, somet

Answer 1

In python, I would write your code as:

actions = {
           1: doOne,
           2: doTwo,
           3: doThree,
          }
actions[i]()

Answer 2

I would go so far as to say that no program should ever use else. If you do you are asking for trouble. You should never assume if it's not an X it must be a Y. Your tests should test for each individually and fail following such tests.

Answer 3

Use a switch/case it's cleaner :p

Answer 4

Use a Ternary Operator!

Ternary Operator(53Characters):

i===1?doOne():i===2?doTwo():i===3?doThree():doNone();

If(108Characters):

if (i === 1) {
doOne();
} else if (i === 2) {
doTwo();
} else if (i === 3) {
doThree();
} else {
doNone();
}

Switch((EVEN LONGER THAN IF!?!?)114Characters):

switch (i) {
case 1: doOne(); break;
case 2: doTwo(); break;
case 3: doThree(); break;
default: doNone(); break;
}

this is all you need! it is only one line and it is pretty neat, way shorter than switch and if!

Answer 5

A switch statement:

switch(i)
{
  case 1:
    doOne();
    break;

  case 2:
    doTwo();
    break;

  case 3:
    doThree();
    break;

  default:
    doNone();
    break;
}

Answer 6

switch (i) {
  case 1:  doOne(); break;
  case 2:  doTwo(); break;
  case 3:  doThree(); break;
  default: doNone(); break;
}

Having typed this, I must say that there is not that much wrong with your if statement. Like Einstein said: "Make it as simple as possible, but no simpler".