PHP Programing language

adplus-dvertising
PHP While loop
Previous Home Next

The while loop is using in PHP Programming when you want to do sum of maximum number of integers, then you can use while loop. The idea of a loop is to do something over and over again until the task has been completed. Before we show a real example of that you might need one, let's go through the structure of the PHP while loop.

Example:

The while loop using with the function , and the while loop is to do a task over and over as long as the specified conditional statement is true. This logical check is the same as the one that appears in a PHP if statement to determine if it is true or false.

while ( conditional statement is true)
{
//do this code;
}

This isn't valid PHP code, Only the displays how the while loop is structured.

  1. The conditional statement is checked. If it is true, then (2) occurs. If it is false, then (4) occurs.
  2. The code within the while loop is executed.
  3. The process starts again at (1). Effectively "looping" back.
  4. If the conditional statement is false, then the code within is not executed and there is no more looping. The code following the while loop is then executed like normal.

Real Example of while Loop are:

Imagine that you are running an Stationary supply store. You would like to print out the price chart for number of copies and total cost. You sell copies at a flat rate, but would like to display how much different quantities would cost. This will save your customers from having to do the mental math themselves.

You know that a while loop would be perfect for this repetitive and boring task. Here is how to go about doing it.

<?php
$copy_price = 5; 
$counter = 10;

echo "<table border=\"1\" align=\"center\">";
echo "<tr><th>Quantity</th>";
echo "<th>Price</th></tr>";
while ( $counter <= 100 ) {
	echo "<tr><td>";
	echo $counter;
	echo "</td><td>";
	echo $copy_price * $counter;
	echo "</td></tr>";
	$counter = $counter + 10;
}
echo "</table>";
?>

Output:

Qua Price
10   50 20   100 30   150 40   200 50   250 60   300 70   350 80   400 90   450 100  50

The loop is creating a new table row and its respective entries for each quantity, until our counter variable grew past the size of 100. When it grew past 100 our conditional statement failed and the loop stopped being used.

Let's review what is going on.

  1. We first made a $copy_price and $counter variable and set them equal to our desired values.
  2. The table was set up with the beginning table tag and the table headers.
  3. The while loop conditional statement was checked, and $counter (10) was indeed smaller or equal to 100.
  4. The code inside the while loop was executed, creating a new table row for the price of 10 brushes.
  5. We then added 10 to $counter to bring the value to 20.
  6. The loop started over again at step 3, until $counter grew larger than 100.
  7. After the loop had completed, we ended the table.
Previous Home Next