Languages

Defining PHP Variables :
A variable is a means of storing a value, such as text string "Hello World!" or the integer value 4. A variable can then be reused throughout your code, instead of having to type out the actual value over and over again. In PHP you define a variable with the following form:

$variable_name = Value;
If you forget that dollar sign at the beginning, it will not work. This is a common mistake for new PHP programmers!

Note: Also, variable names are case-sensitive, so use the exact same capitalization when using a variable. The variables $a_number and $A_number are different variables in PHP's eyes.

PHP Variable Example :
Say that we wanted to store the values that we talked about in the above paragraph. How would we go about doing this? We would first want to make a variable name and then set that equal to the value we want. See the following example :

PHP Code:
<?php
$hello = "Hello World!";
$a_number = 4;
$anotherNumber = 8;
?>

Note for programmers: PHP does not require variables to be declared before being initialized.

PHP Variable Naming Conventions :
There are a few rules that you need to follow when choosing a name for your PHP variables.

PHP variables must start with a letter or underscore "_".
PHP variables may only be comprised of alphanumeric characters and underscores. a-z, A-Z, 0-9, or _ .
Variables with more than one word should be separated with underscores. $my_variable
Variables with more than one word can also be distinguished with capitalization. $myVariable.