loops & labels

[Anupreet Arora]

What will be the result of attempting to compile and run the following program?

 
public class Q28fd {
    public static void main(String[] args) {
        int counter = 0;
        l1:
        for (int i=0; i<10; i++) {
            l2:
            int j = 0;
            while (j++ < 10) {
                if (j > i) break l2;
                if (j == i) {
                    counter++;
                    continue l1;
                }
            }
        }
        System.out.println(counter);
    }
} 

Am I allowed to use labels anywhere inside code..loop or no loop?

[Alton Hernandez]

Hi Anupreet,
I think your program will fail compilation because the label i2 is proceeded by the variable declaration of j. Labels must immediately follow a block of codes like those enclosed by for-loop, while, or just simply {}.

[Marlene Miller]

According to JLS 17.7, any statement may have a label prefix.
Identifier : Statement
Now, it is important to know what is Not a Statement.
int i = 1; // Not a Statement
label1 : i = 2;
label2 : i++;
label3 : {}
one: two: three: if (i > 0) break two; else i++;
As far as I can tell, local variable declarations and local class declarations are not Statements.
void m() {
label1 : int i = 1; // No!
label2 : class C {} // No!
}

[Alton Hernandez]

Originally posted by Marlene Miller:
According to JLS 17.7, any statement may have a label prefix.

That's interesting.
In that case, this is also allowed:
label1:;