using switch case?

[maggie karve]

public class Agre{
    private static int x; 
    private static int y;
    public static void main(String args[]){
         x=(int)3.9;
         y=(int)3.1;
         switch(x){
              case y: System.out.print("Received ");
              default: System.out.print("Not received ");
         }
         System.out.println("THE END");
    }
}    

compile time error???
answer is
constant expressions needed???x and y are not constants...
what does this mean??

[saima kanwal]

the problem is with variable y: it should be a constant (that is should be marked final) and it should be a compile time constant which means that y should be declared and initialized at the same time.Refer to page 336 Chapter 5 of K & B .

so the correct code is :

public class Agre{  
        private static int x;   
        private static final int y=(int)3.1;  
        public static void main(String args[]){  
             x=(int)3.9;  
               
             switch(x){  
                  case y: System.out.print("Received ");  
                  default: System.out.print("Not received ");  
            }  
            System.out.println("THE END");  
       }  
   }      

[Ankit Garg]

maggie you are not following the quoting of source rule properly. You've asked a lot of questions without a proper source (like this, this, this and this). Quoting source is not optional at javaranch. If you don't quote the source properly, then we might have to delete your questions...

[maggie karve]

ok..i will do that from next post..actually i am trying lots of code on my own too.so its a combination of all that..anyways i will take care from next time....

[Jesper de Jong]

maggie joseph wrote:ok..i will do that from next post..

No. Tell us what the source of the above question is now. As you've been told multiple times, it's required on JavaRanch.

[Abimaran Kugathasan]

The case constant must be a compile time constant! Since the case argument has to be resolved at compile time, that means you can use only a constant or final variable that is assigned to literal value.

I think, this may help to you.!

[Alpesh Rathod]

Abimaran Kugathasan wrote:The case constant must be a compile time constant! Since the case argument has to be resolved at compile time, that means you can use only a constant or final variable that is assigned to literal value.

I think, this may help to you.!

Very good very good...

[maggie karve]

question is from Examlab most probably.....