Core PHP: Variables (2.0)

Variables

Variables are used as "containers" in which we store information.
A PHP variable starts with a dollar sign ($), which is followed by the name of the variable.

$variable_name = value;

Rules for PHP variables:
- A variable name must start with a letter or an underscore
- 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 ($name and $NAME would be two different variables)

For example:

<?php
   $name = 'John';
   $age = 25;
   echo $name;

  // Outputs 'John'
?>

In the example above, notice that we did not have to tell PHP which data type the variable is.
PHP automatically converts the variable to the correct data type, depending on its value.

Unlike other programming languages, PHP has no command for declaring a variable. It is created the moment you first assign a value to it.