PHP Beginners Guide #1

Best Forumer,

I would like you to explain how php works, many people think they know something about PHP, but it is often not correct. Let's start with the basics!

Chapter 1: Variables

§ 1: Introduction
Variables can be used to temporarily store data. Such information may consist of numbers (integers) or pieces of text (strings), but can also be true / false data (booleans) or a set of data (array) contain. All we can create in PHP, we can put in a variable.

§ 2: Creating variables
Creating a variable, also called declaration, done by one U.S. dollars sign ($) followed by a random name. With the equal-to (=) sign, we can then assign a value to the variable. Finally, we close the line with a semicolon.

[php]<?php
$text = 'Hello World!';
echo $text;
?>[/php]

This piece of code we declare the variable $text, adding the value "Hello World!" to it. Then we use an echo to the contents of $text to put on screen. The output is as follows:

Hello World!

§ 3: different types of variables

As I mentioned earlier, we can actually save everything in a PHP variable. Depending on the content of a variable belongs to a particular type. Some examples:

[php]<?php
$text = 'Hello World!'; // String
$age = 28; // Integer
$price = 190.75; // Float
$check = false; // Boolean
?>[/php]

Here are some examples of different types of variables. The first variable $text we have already seen and contains a string. If you store numbers in one variable, it is an integer, a float if you concern about the numbers have decimal. If a variable includes true or false, you call it a boolean. A type variable that is not in this example is the array. On this variable I will make a separate tutorial.

As we will see a string in PHP is placed between single quotes. In an integer, float or boolean we do not use quotes!

§ 4: Calculating with variables
We have already seen that we can echo variables, but that's not all. Calculating with variables in PHP is something that we will use frequently. Some examples:

[php]<?php
$amout = 10;
$price = 9.95;
$btw = 0.19; // 19%

$subtotal = $amout * $price; // Calculate subtotal
echo 'Subtotal: '.$subtotal.'<br />';

$aBtw = $subtotal * 0.19; // aBtw = After BTW Calculate BTW
$total = $subtotal + $aBtw; // Calculate Total
echo 'Total: '.$total;
?>[/php]

Output:

Subtotal: 99.5
Total: 118.405

This was Chapter 1, soon I will go to the next chapter.