PHP Constants
Constants are same as variables but the value of constants cant be changed after they are defined. Constant name starts with a letter or underscore. Constant name declaration rules are same as a variable. But it doesn’t define with “$” sign. Constant is always global.
Syntex
define(name, value, case-sensitive)
Parameters:
- name: name of the constant
- value: the value of the constant
- case-insensitive: whether the constant name should be case-insensitive. It can be only true or false. Default is false.