when arithmetic opearations are performed

[Vaibhav Chauhan]

I was is happy with my concept that arithmetic operations are performed at runtime and compiler doesn't bother about it until i see the output of following code:

public class TestFinalVariables {

public static void main(String []argv)
{
final int firstInt=12, secondInt=5;
byte b=firstInt+secondInt;

System.out.println("7 + 5: "+b);
}
}

compiler doesn't complain anything wrong in the code and output is
"7 + 5= 12"

but compiler starts complaining that int can't be converted to byte when i make following changes:

final int firstInt=125, secondInt=5;

it means that arithmatic operations are performed at compile time ???
confused

[Chetan Raju]

Since you are using final constants and adding them up and assigning them to a byte variable, the checking is performed at compile time itself since they are constant evaluations. And since the addition operation goes out of range you get a compiler error.

[Vaibhav Chauhan]

thanks for reply, chetan

you mean that if i add variables (which are not final) then the addition is performed at runtime otherwise at compile time.

[wise owen]

15.28 Constant Expression