PHP Tutorial

A web server programming language.

Chapter Quiz Exercises
Course Topics
PHP Intro PHP Syntax PHP Variables PHP Echo / Print PHP Data Types PHP Strings PHP Numbers PHP Math PHP Constants PHP Operators PHP If...Else...Elseif PHP Switch PHP Loops PHP Functions PHP Arrays PHP Superglobals PHP Form Handling PHP Date and Time PHP File Handling PHP Cookies PHP Sessions PHP Exceptions PHP OOP Classes & Objects PHP Constructor MySQL Connect MySQL Insert Data MySQL Select Data PHP JSON PHP Regular Expressions PHP Include & Require

PHP Constants

PHP Constants

Constants are like variables except that once they are defined they cannot be changed or undefined.

Create a PHP Constant

To create a constant, use the define() function.

Syntax: define(name, value, case-insensitive)

  • name: Specifies the name of the constant
  • value: Specifies the value of the constant

Constants are global and can be used across the entire script.

Try It Yourself

Edit the code below and click Run to see the result live.

Source Code
Result
Topics
PHP Intro PHP Syntax PHP Variables PHP Echo / Print PHP Data Types PHP Strings PHP Numbers PHP Math PHP Constants PHP Operators PHP If...Else...Elseif PHP Switch PHP Loops PHP Functions PHP Arrays PHP Superglobals PHP Form Handling PHP Date and Time PHP File Handling PHP Cookies PHP Sessions PHP Exceptions PHP OOP Classes & Objects PHP Constructor MySQL Connect MySQL Insert Data MySQL Select Data PHP JSON PHP Regular Expressions PHP Include & Require