• PHP Video Tutorials

PHP - Break Statement

The break statement along with the continue statement in PHP are known as "loop control statements". Any type of loop (for, while or do-while) in PHP is designed to run for a certain number of iterations, as per the test condition used. The break statement inside the looping block takes the program flow outside the block, abandoning the rest of iterations that may be remaining.

The break statement is normally used conditionally. Otherwise, the loop will terminate without completing the first iteration itself.

The syntax of break statement is as follows −

while(expr){
   if (condition){
      break;
   }
}

The following flowchart explains how the break statement works −

PHP Break Statement

Example

The following PHP code is a simple example of using break in a loop. The while loop is expected to perform ten iterations. However, a break statement inside the loop terminates it when the counter exceeds 3.

<?php
   $i = 1;

   while ($i<=10){
      echo "Iteration No. $i \n";
      if ($i>=3){
         break;
      }
      $i++;
   }
?>

It will produce the following output −

Iteration No. 1
Iteration No. 2
Iteration No. 3

An optional numeric argument can be given in front of break keyword. It is especially useful in nested looping constructs. It tells how many nested enclosing structures are to be broken out of. The default value is 1, only the immediate enclosing structure is broken out of.

Example

The following example has three nested loops: a for loop inside which there is a while loop which in turn contains a do-while loop.

The innermost loop executes the break. The number "2" in front of it takes the control out of the current scope into the for loop instead of the immediate while loop.

<?php
   for ($x=1; $x<=3; $x++){
      $y=1;
      while ($y<=3){
         $z=1;
         do {
            echo "x:$x y:$y z:$z \n";
            if ($z==2){
               break 2;
            }
            $z++;
         }
         while ($z<=3);
         $z=1;
         $y++;
      }
   }
?>

It will produce the following output −

x:1 y:1 z:1
x:1 y:1 z:2
x:2 y:1 z:1
x:2 y:1 z:2
x:3 y:1 z:1
x:3 y:1 z:2

Note that each time the value of "z" becomes 2, the program breaks out of the "y" loop. Hence, the value of "y" is always 1.

Advertisements