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Monday, August 19, 2013

Contro strucrutes in Php: continue

continue is used within looping structures to skip the rest of the current loop iteration and continue execution at the condition evaluation and then the beginning of the next iteration.
Note: Note that in PHP the switch statement is considered a looping structure for the purposes of continue.
continue accepts an optional numeric argument which tells it how many levels of enclosing loops it should skip to the end of.

<?php
while (list($key, $value) = each($arr)) {
    if (!($key % 2)) { // skip odd members
        continue;
    }
    do_something_odd($value);
}

$i = 0;
while ($i++ < 5) {
    echo "Outer<br />\n";
    while (1) {
        echo "  Middle<br />\n";
        while (1) {
            echo "  Inner<br />\n";
            continue 3;
        }
        echo "This never gets output.<br />\n";
    }
    echo "Neither does this.<br />\n";
}
?>


Omitting the semicolon after continue can lead to confusion. Here's an example of what you shouldn't do.

<?php
  for ($i = 0; $i < 5; ++$i) {
      if ($i == 2)
          continue
      print "$i\n";
  }
?>


One can expect the result to be :

0
1
3
4


but this script will output :

2


because the return value of the print() call is int(1), and it will look like the optional numeric argument mentioned above.
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