PHP While Loop Examples

The while loop allows you to execute a certain code a specified number of times. Let's study its operation with examples.

Example

Let's output a string of numbers from 1 to 9:

<?php
	$i = 1;
	while ($i <= 9) {
		echo $i;
		$i++;
	}
?>

Code execution result:

123456789

Example Breakdown

To solve the problem, a counter variable is introduced, most often it is called $i. This variable is assigned an initial value before the loop, in our case 1.

Then the loop termination condition is set, in our case it is the condition $i <= 9. It means that the loop runs as long as $i is less than or equal to 9.

Inside the loop, we must increment the counter variable so that the loop stops eventually. In our case, we will increase $i by 1 using the command $i++.

Example

Let's output a column of numbers from 1 to 5. To do this, we will add the br tag during output:

<?php
	$i = 1;
	while ($i <= 5) {
		echo $i . '<br>';
		$i++;
	}
?>

Example

Let's find the sum of numbers from 1 to 5. For this, a variable is introduced in which the sum will be accumulated, in our case it is the variable $sum.

To find the sum, we will each time add to this variable its current value plus the content of the variable $i:

<?php
	$i = 1;
	$sum = 0;
	while ($i <= 5) {
		$sum += $i;
		$i++;
	}
?>

Code execution result:

15

How it works: at the beginning $sum is 0, then on the first pass of the loop it becomes 0 + 1 = 1, on the next pass of the loop it becomes 1 + 2 = 3 and so on until the loop ends.

PHP While Loop Examples

Example

Example Breakdown

Example

Example

See Also