PHP BASICS

- A constant is similar to a variable in the sense that you can store information in a keyword that can be used throughout your web page.

- However, the value of a constant cannot be changed, unlike a variable. It's literally "constant".

- It's also worth noting that constants are case-sensitive and are written in ALL CAPS by convention.

- The keyword 'define' is used in defining a constant in PHP:

define("TITLE", "Defining Constants");

- The first argument must be in quotes (string) and represents the name of the constant.

- The second argument is also a string and represents the value of the constant.

- The two arguments are seperated by a comma, enclosed within a bracket and ends with a semi-colon (;).

- To display a constant on your page, you can echo it using PHP , like this:

< ?php echo TITLE; ?>