In one of our previous posts we talked about creating variables in PHP. In this post we will talk about constants in PHP.
In programming, constants are like variables except that once they are defined they cannot be changed or undefined.
In PHP, a constant starts with a letter or underscore. The value cannot be changed during the script. One thing to be noted is that Constants are automatically global and can be used across the entire script.
To learn more about syntax and details about constant in PHP, click here.