Undefined Label with jmp1

[Zulfi Khan]

Hi,
I am getting Label error on Apache NetBeans 12.3

Undefined Label with jmp1

package com.mycompany.continuelabel;

/**
 *
 * @author zulfi
 */
public class MainContinue {
   
      public static void main(String[] args) {
        int b=10;
        int a= 5;
        jmp0:
          while (b> 10)
          { if (a>5)
              continue jmp0;
            else
              continue jmp1;
          } 
        jmp1: System.out.print("Zulfi");
          }

}

Somebody please guide me.

Zulfi.

[Carey Brown]

A continue or break label must appear immediately before the loop construct; "while( b > 10 )" in your case. So, "jmp1" does not follow this rule.

[Campbell Ritchie]

Carey Brown wrote:. . . immediately before the loop construct . . .

I never knew that. Not that I use break; and continue; anyway. It is in the JLS (=Java® Language Specification).

[Paul Clapham]

To put it another way: break and continue are not equivalent to the dreaded go to.

[Campbell Ritchie]

Not if the label has to precede them, no they aren't. As I said, I only learnt that yesterday, from this thread.

[Matthew Bendford]

Fun fact: goto is a reserved keyword but actually causes a compile-time error when tried to be used as in Batch or similar script languages.

@OP
Labels are only rarely used to escape layered loops:

outloop:
while(bool)
{
    //inner loop
    while(bool2)
    {
        if(escapeCondition)
            break outloop;
    }
}

Although there're maybe some edge cases where this could be a valid option if you extract it into its own method one doesn't need the label nor the break but can use return instead.
Or TLDR: Although it's valid code there's pratically no reason to actually use it in production.