Task Eight - Do Loop - PHP Tutorial

This program repeatedly allows you to enter a number.

It calculates the running total of the numbers you entered.

This program uses a "do" loop. There is more information about "do" loops here.

Here is a structure diagram of the program.

Here is the result of running the program.

Here is the program code.


<?php

$total = 0;

do
{
  echo "Enter a whole number (0 to quit) ... ";
  $input = fgets(STDIN);

  $total = $total + $input;

  echo "\n\nThe running total is $total.\n\n";

}
while ($input <> 0);   // While $input is not equal to zero

echo "\n\nFinished.\n\n";

?>

Code

Explanation

$total = 0;

Initialise $total to zero. A common program bug is when you forget to initialise a variable. Many programming languages allow this to happen and the variable contains garbage data until it is initialised.

do
{
// Block of code here
}
while (Boolean};

This is the structure of the do loop.

The code block between the curly brackets is repeated as long as the boolean is true.

Learning Tasks

8 (a) Write a program that calculates the average of the input numbers. It should

calculate the running total of the input numbers. (The program above does this).
count how many numbers have been input.
display the count, the running total and the average each time a new number is input.
quit if zero is entered.

8 (b) Draw a structure diagram of your program. It will be similar to the one at the top of this page.