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SWITCH statement .

 
Greenhorn
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Source : SCJP Java 2 by Kathy Sierra & Bert Bates.

import java.io.*;

public class Switch{


public static void main(String args[])
{
final int one =1 ;
final int two = 2 ;
int x = 1;
switch(x)
{
case one :

System.out.println("one");
break ;
case two :
System.out.println("two");
break ;
}
}

}

When I compiled the above program it compiled and executed correctly with an output one.

The above code uses final variables in a case statement . Note that if the final keyword is omitted , the above will not compile.


I understood that if we omit the final keyword , this will not compile but I did not understand why it compiled and executed properly if we add the final variable . Can anyone please explain it in detail ?

Thanks in advance .
[ September 11, 2007: Message edited by: Rakesh Yelugoila ]
 
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A switch label must represent a compile-time constant. If these variables were not final with their values known at compile time, then they could not be used as switch labels.
 
Ranch Hand
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Those are case constants. They can't be changed. By putting a variable there you have to use variables that are declared final. Anything goes there has to be some kinda of constants one way or other.
 
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