PHP Programming/The do while Loop

The do while loop

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

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

PHP Code:

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

PHP Output:

120

HTML Render:

120

The continue statement

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

• PHP Manual: Control Structures: do-while