Defining a constant in PHP can come in handy when working with a value that will be used throughout your script. What is a constant exactly? According to PHP.net, “A constant is an identifier (name) for a simple value“. One important thing you need to know is that, like its name states, a constant cannot be changed. That is pretty much the main difference between a constant and a variable.
Here is a basic example:
Simple enough. Just remember that constants are case sensitive, so this wouldn’t work:
Unless, of course, you set a third parameter within the define()
function to control the case. By default, it is set to false
, which is case-sensitive. To make it case-insensitive, all you need to do is set that third parameter to true
.