This highly interactive course introduces you to fundamental programming concepts in PHP, one of the most popular languages in the world. It begins with a simple Hello world program and proceeds on to cover common concepts such as Conditional Statements, Loop Statements, and Logic in PHP. 

It then reflects upon the idea of Functions and Arrays, as well as the power they give to the programmer to write better code. 

Finally, it dives deeper in order to teach about advanced concepts such as Classes, Inheritance and Exception Handling in PHP. By the time you're done, you'll have a good grip on the basics of PHP, and will be ready to study advanced concepts.

Learn PHP from Scratch

## Defining Constants
Constants, by definition, are variables that cannot be modified during the execution of the script. They are created using the `const` statement or the `define` function. 
> **Convention:** In PHP, the convention is to use uppercase letters for constant names, e.g., `A_CONSTANT`.

The following code snippet shows how constants are created:

# Defining Constants
Constants, by definition, are variables that cannot be modified during the execution of the script. They are created using the `const` statement or the `define` function. 
> **Convention:** In PHP, the convention is to use uppercase letters for constant names, e.g., `A_CONSTANT`.

The following code snippet shows how constants are created:

This lesson discusses all there is to know about constants, i.e., defining them, checking if they're defined and using them in PHP programs.

Getting Started

Variables

Operators

Conditional Statements

Loops

Functions

Strings

Arrays

PHP Assessment 1

Classes and Inheritance

Exception Handling

PHP Assessment 2

Constants

Defining Constants #