What is meant by a number after "break" or "continue" in PHP?

kn3l picture kn3l · Mar 2, 2011 · Viewed 56.1k times · Source

Could someone please explain, with examples, what is meant by loop break 2 or continue 2 in PHP? What does it mean when break or continue is followed by a number?

Answer

Your Common Sense picture Your Common Sense · Mar 2, 2011
$array = array(1,2,3);
foreach ($array as $item){
  if ($item == 2) {
    break;
  }
  echo $item;
}

outputs "1" because the loop was broken forever, before echo was able to print "2".

$array = array(1,2,3);
foreach ($array as $item){
  if ($item == 2) {
    continue;
  }
  echo $item;
}

outputs 13 because the second iteration was passed

$numbers = array(1,2,3);
$letters = array("A","B","C");
foreach ($numbers as $num){
  foreach ($letters as $char){
    if ($char == "C") {
      break 2; // if this was break, o/p will be AB1AB2AB3
    }
    echo $char;
  }
  echo $num;
}

outputs AB because of break 2, which means that both statements was broken quite early. If this was just break, the output would have been AB1AB2AB3.

$numbers = array(1,2,3);
$letters = array("A","B","C");
foreach ($numbers as $num){
  foreach ($letters as $char){
    if ($char == "C") {
      continue 2;
    }
    echo $char;
  }
  echo $num;
}

will output ABABAB, because of continue 2: the outer loop will be passed every time.

In other words, continue stops the current iteration execution but lets another to run, while break stops the whole statement completely.
So we can ell that continue is applicable for the loops only, whereas break can be used in other statements, such as switch.

A number represents the number of nested statements affected.
if there are 2 nested loops, break in the inner one will break inner one (however it makes very little sense as the inner loop will be launched again in the next iteration of the outer loop). break 2 in the inner loop will break both.