PHP Programming/do while loop

From Wikibooks, open books for an open world
Jump to: navigation, search

Return to PHP.

The do while loop[edit]

The do while loop is similar in syntax and purpose to the while loop. The do/while loop construct moves the test that continues the loop to the end of the code block. The code is executed at least once, and then the condition is tested. For example:

  <?php
  $c = 6;
  do {
    echo 'Hi';
  } while ($c < 5);
  ?>

Even though $c is greater than 5, the script will echo "Hi" to the page one time.

PHP's do/while loop is not commonly used.

Example[edit]

This example will output the factorial of $number (product of all the numbers from 1 to it).

Crystal Clear app terminal.png PHP Code:

$number = 5;
$factorial = 1;
do {
	$factorial *= $number;
	$number = $number - 1;
} while ($number > 0);
echo $factorial;

Crystal Clear app kscreensaver.png PHP Output:

120

Crystal 128 yast default.png HTML Render:

120


The continue statement[edit]

The continue statement causes the current iteration of the loop to end, and continues execution where the condition is checked - if this condition is true, it starts the loop again. For example, in the loop statement:

<?php
    $number = 6;
    for ($i = 3; $i >= -3; $i--) {
        if ($i == 0)
            continue;
        echo $number . " / " . $i . " = " . ($number/$i) . "<br />";
    }
?>

the statement is not executed when the condition i = 0 is true.

For More Information[edit]