Dart Break and Continue

The break command ends a loop at once. The continue command skips the rest of one run and moves to the next run.

Breaking out of a loop

The loop counts toward 5, but break fires at 3. Only the numbers 1 and 2 reach the screen.

void main() {
  for (var i = 1; i <= 5; i++) {
    if (i == 3) {
      break;
    }
    print(i);
  }
}

Skipping one run

The continue line fires at 3, so that run prints nothing. The other runs print as normal.

void main() {
  for (var i = 1; i <= 5; i++) {
    if (i == 3) {
      continue;
    }
    print(i);
  }
}

Breaking out of a for in loop

The loop visits values in order and break fires at 15. The value 16 never reaches the screen.

void main() {
  for (var n in [4, 8, 15, 16]) {
    if (n == 15) {
      break;
    }
    print(n);
  }
}

Code after a break

The break ends the loop at 2. The print below the loop still runs after the break.

void main() {
  for (var i = 1; i <= 5; i++) {
    if (i == 2) {
      break;
    }
    print(i);
  }
  print('Loop ended');
}

Example

void main() {
  for (var i = 1; i <= 6; i++) {
    if (i == 2 || i == 4) {
      continue;
    }
    print(i);
  }
}

Key points

Use break to leave a loop before its normal end.
Use continue to skip the rest of the current run.
After continue, the loop moves on to its next run.
After break, the code below the loop runs next.
Both commands often sit inside an if block in the loop.

In this example, the counter runs from 1 to 6. The if test catches the counter at 2 and at 4. The continue command skips the print on those two runs. The other runs print 1, 3, 5, and 6.

Try it Yourself

Edit the code, then press Run.

Running is simulated · DartPad

void main() {
  for (var i = 1; i <= 6; i++) {
    if (i == 2 || i == 4) {
      continue;
    }
    print(i);
  }
}

Exercise

What does continue do inside a loop?

It ends the whole loop It skips the rest of the current run It restarts the program It prints the counter