Constants for beginners to PHP

Constant; frequently used things, some important values ​​do not want to be changed. The antonym of variable can be understood as a hard-coded, unchanging value, similar to a person’s name,

Naming convention;

1. Basics and constants Similar, see the previous blog for details

2. In order to distinguish it from variables, usually all letters are capitalized

Features;

1. After it is defined, the value cannot be changed

2. After it is determined, the name cannot be used for anything else. It can represent this value

3. After definition, it can be called in any corner of the current page

Assignment type; Integer, floating point, string, Boolean, NULL

Definition;

1. Method; define ("constant name', "constant value", "whether it is case-sensitive") The third parameter can be omitted, the default is false

2. Quote; directly in the current page To reference the defined constant name

to a constant reference defined in another page, use include ("the name of the page where the constant is located") to load that page and then reference it

The above has introduced the constants for beginners to PHP, including relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.