Is it possible to have ranges in switch() and case?

Answers

• GoToLoop

  February 2014 edited February 2014 Answer ✓

  Inside switch, most we can do is chained case:

  case 1: case 2: case 3: case 4: case 5: case 6: ... case 59: case 60: println("a"); break;

  But we'd still have to type lotsa conditions anyways! :o3

  switch/case wasn't made for complex arrangements. For such, we gotta use if/else if/else blocks! 8-|

  http://docs.oracle.com/javase/tutorial/java/nutsandbolts/switch.html
• TfGuy44

  February 2014 edited February 2014 Answer ✓

  If the value you're switching on is an int, you might also consider having a lookup array.

  String[] lookup = {"a","a","a",...,"b","b",...,"c"}
  println(lookup[num]);
  
• Chrisir

  February 2014 edited February 2014 Answer ✓

  you could put the ranges into a separate function to prepare for switch

  ;-)

      int valueForSwitch = funcMapValueForSwitch (num);
  
      switch (valueForSwitch) {
  
     case 0:
     //
     break;
  
     case 1:
     // 
     break;
  
     case 2:
     // 
     break;
  
     case -1:
     // do nothing 
     break;  
  
     default:
     // error 
     println ("error code 967");
     break; 
  
      }
  
      ...
  
      int  funcMapValueForSwitch ( int numLocal ) {
      if (numLocal>=1 && numLocal <= 60) return 0;
      if (numLocal>=61 && numLocal <= 100) return 1;
      if (numLocal>=101 && numLocal <= 109) return 2;
      // default : 
      return -1;
      }
  

  you can also use global consts to name the entries for case (and use them in the func and in switch) :

  final int rangeIs1_60 = 0;
  final int rangeIs61_100 = 1;
  final int rangeIs101_109 = 2;
  final int rangeIsUnknown = -1; 
  
• pojken

  February 2014

  Thanks for the replies, everyone!

  I think the easiest one for me now might be using TFGuy44.
• KevinWorkman

  February 2014 Answer ✓

  No offense, but using a "lookup array" for mostly the same value is a pretty bad idea. You're much better off using basic if statements instead:

  if(num >= 1 && num < 60) {
      println("a");  
  }
  else if(num <100){
      println("b");  
  }
  else if(num < 109){
      println("c");  
  }