Question

68

Is there an alternative to using IF / ELSE statements

rated 0 times [ 71] [ 3] / answers: 1 / hits: 35696 / 11 Years ago, wed, october 9, 2013, 12:00:00

Question

More out of curiosity, but I was wondering how to refactor an if statement to something cleaner / less brittle. From what I have read, polymorphism could have a use?

In the example I only want to return the first car if color:'red' is true.

Coffeescript

example: () ->

    cars = [{color:'red', reg:'111'},{color:'blue', reg:'666'}]

    if cars[0].color is 'red' 

    then cars[0]

    else cars[1]

Javascript

  example: function() {

    var cars = [{color:'red',reg:'111'},{color:'blue',reg:'666'}];

    if (cars[0].color === 'red') {

      return cars[0];

    } else {

      return cars[1];

    }

  }

I understand this question maybe closed or moved due to the ambiguous nature

Answers

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jaylynbrynnk

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answered 11 Years ago sherryd · Accepted Answer

? : operator is exactly that, a cleaner if-else

http://msdn.microsoft.com/en-us/library/ty67wk28.aspx

classify = (input < 0) ? negative : positive;

There are also switch statements for larger combinations:

http://www.w3schools.com/js/js_switch.asp

switch(n)

{

case 1:

  execute code block 1

  break;

case 2:

  execute code block 2

  break;

default:

  code to be executed if n is different from case 1 and 2

}

Polymorphism is an abstract concept, not a way to write a statement. It's the practice of creating a method/function/class/etc where type is at least SOMEWHAT ambiguous. So the same method could return a result if fed, say, an integer for parameter 1, the same as if you were to feed an array into the same parameter.