Final variables in switch

[Seema Ahuja]

I hv a doubt here.

we all know that final variables cannot be changed.

so how come the following code works?

final int x =2;
for(int z =0;z<4;z++)
{
switch(x)
 
case x: System.out.println("One");
case x-1: System.out.println("two");
case x-2: System.out.println("zero");
   

can anyone please tell me why is it letting me modify the final variable x??

Thanks

[steven gerrard]

ur not modifying the final variable
since x is final x-1 is another final
value of x does not change
its like saying
case (y=x-1):

[vignesh kaladi]

hi
here final valued not changed;




class vignesh
{
public static void main(String[] args) throws Exception
{
final int x =2;
for(int z =0;z<4;z++)
{
switch(x)
{
case x: System.out.println("One");break;
case x-1: System.out.println("two");break;
case x-2: System.out.println("zero");
}
}
}
}

o/p:
one
one
one
one

[Sumit Jain]

Basically, key word final is acting a constant to a variable.
so ,final int x =2; means x = 2 and is fixed(Const)through out the code.

Now for case x: //nothing but x=2;
case x-1://it will not assign the value to x but it wiil evalute as (2-1) = 1.
case x-2://same as above except evalute as (2-2) = 0.

So, In a nutcell you can't modify the value of x but you can use it for any mathematical expression as constant.

Hope It will help.
Regards,
Sumit Jain