Can you `break` from multiple loops like PHP can by passing a number?

Question

If you are in a 3rd nested loop in PHP, you can do break 3; and break all loops up 3 levels.

break seems to work in C. But if I do break 3 I get a syntax error. I guess it doesn't support it.

What is the best way to break multiple loops? Should I set a flag which is checked up the loops - and breaks if it is set?

Is there anything more elegant?

Answer 1

You could use goto, but:

Answer 2

Sometimes goto is the most elegant solution.

Answer 3

I also agree. goto has its uses and this is one of the main ones.

Answer 4

The usual solutions are:

• flags or other state checked in each of the nested loops
• goto a label after the end of the outer loop
• refactor your code so that the nested loops are in a function of their own. Use return to in effect break from the outermost loop.

Answer 5

Steve Jessop's answer arrived a few seconds before I was ready to post my answer. I have one suggestion to add to his, although it may not be considered elegant - throw an exception.

Answer 6

Another way besides goto is to use a shared variable in all of the conditional portions of the for loops. This shared variable can be used like a kill switch for the loop.

bool done = false;
for (int i = 0; i < someNum && !done; i++ ) {
  for ( int j = 0; j < someOtherNum && !done; i++ ) {
    for ( int j = 0; j < again && !done; i++ ) { 
      if ( someCondition ) { 
        done = true;
        break;
      }
    }
  }
}