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A blog site which I am posting to during my learning of the popular programming language PHP. Feel free to leave comments!

• PHP - Conditional Statements

  Posted on April 6th, 2009 admin No comments

  In PHP, you can use Conditional Statements to make decisions. Let’s say you wanted to give your customer a discount if he/she has an order over £5 (I know I’m generous!). You can easily do this by using the ‘If’ statement.

  Let’s create the IF statement:

  <?php

  define(’CHOCOLATECAKE’, 3.50);
  define(’SWISSROLL’, 1.50);

  $subtotal = CHOCOLATECAKE + SWISSROLL;

  echo “Sub total of your order: £” . $subtotal . “. Thanks for visiting! “;

  if( $subtotal >= 5.00 )

  {

  $totalcost = ($subtotal * 0.90);

  $grandtotal = number_format($totalcost,2);

  echo “This order qualified for a discount! “;

  echo “Your grand total is: £” . $grandtotal;

  }

  else {

  $subtotal = number_format($subtotal,2);

  echo “Your grand total for your order is £” . $subtotal;

  }

  ?>

  As you may notice I am charging customer’s 3.50 for the cake and 1.50 for the swiss roll. If the customer bought both of these (equalling £5) it would be eligable for discount!  The basic princpiple is that if the $subtotal is over the value of 5 then it creates a new variable called $totalcost. The $totalcost is worked out by the $subtotal being multiplied by 0.90 to subtract 10% off the order.

  You will also notice there is an ‘Else’ function in there as well. If the ‘If’ function turns false (as in the order is below £5) the ‘Else’ function is performed. The Else funtion in this script will output the $subtotal variable if the order is below £5

  The layout of writing an IF statement is as follows:          if (your argument here) {commands here}

  (Post created on Monday, April 6th 09 at 17:30)

  PHP Conditional Statements, Constants, Else Function, IF Function, PHP, Variables

• PHP - Constants

  Posted on April 6th, 2009 admin 1 comment

  A constant in PHP stores a value like a variable but if a Constant is given a value it can’t be changed in the script.

  To declare a constant you have to set it out in the following way. Let’s say we wanted to give a chocolate cake a fixed price:

  define(’CHOCOLATECAKE’, 1.50);

  or even a swiss roll! ummm

  define(’SWISSROLL’, 1.25);

  If you wanted to use  a constant all you have to do is use the name of the Constant such as:

  echo CHOCOLATECAKE;

  or even:

  echo SWISSROLL;

  Using these Constants will obviously output the price to the browser. You can use these constants to work out the total cost of both by using Variables and Constants together:

  $totalcost = CHOCOLATECAKE + SWISSROLL;

  The $totalcost now has a value of 2.75 and subsequently this variable is now of the ‘float’ data type as it’s a decimal number. You can see why PHP is a very good language to build customer order forms etc. You now have a variable that has a value and we can now output this to the browser:

  echo “Total cost of your order: £” . $totalcost . “. Thanks for visiting!”;

  As you can see you can effectively use constants and variables together!

  (Post created on Monday, April 6th 09 at 14:15)

  PHP Constants, Declaring Constants, Float, Variables