Variables are "containers" for storing information.
Creating (Declaring) PHP Variables
In PHP, a variable starts with the $ sign, followed by the name of the variable:
$txt = "Hello world!";
$x = 5;
$y = 10.5;
After the execution of the statements above, the variable $txt will hold the value Hello world!, the variable $x will hold the value 5, and the variable $y will hold the value 10.5.
Note: When you assign a text value to a variable, put quotes around the value.
Note: Unlike other programming languages, PHP has no command for declaring a variable. It is created the moment you first assign a value to it.
A variable can have a short name (like x and y) or a more descriptive name (age, carname, total_volume).
Rules for PHP variables:
- A variable starts with the $ sign, followed by the name of the variable
- A variable name must start with a letter or the underscore character
- A variable name cannot start with a number
- A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
- Variable names are case-sensitive ($age and $AGE are two different variables)
The PHP echo statement is often used to output data to the screen.
The following example will show how to output text and a variable:
$txt = "W3Schools.com";
echo "I love $txt!";