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

pojken

Hello,

Say I need to sort a range of items, is there a way to do that using switch?

switch(num) {
  case 1..60: 
    println("a");  
    break;
  case 61..100: 
    println("b");  
    break;
  case 101..109: 
    println("c");  
    break;
}

I can't seem to find a solution and would rather not have to use a bunch of if statements.

Thanks!

Tien

GoToLoop

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

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

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

Thanks for the replies, everyone!

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

KevinWorkman

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");  
}