PHP variables, PHP variable _ PHP Tutorial

PHP variables. In PHP, the variable program in PHP is composed of two parts: code and data. data is stored in the variable. the essence of the variable is a storage space in the memory. Empty PHP variable corresponding to the variable, PHP variable
Variables in PHP

A program is composed of two parts: code and data. data is stored in variables. the essence of a variable is a storage space in memory. The space corresponding to the variable has a sub-name called the variable name, which is used to read and write data.

Variable definition

The '$' symbol must be used before the php variable name, or '$' is the syntax structure that defines the variable.

Example:

Variable access

Echo variable name;

Example:

Variable modification

Variable name = value;

Deletion of variables

Unset (variable name );

Example:

Variable naming rules:

1. it must start with '$'

2. only letters, numbers, and underscores are allowed.

3. the '$' symbol cannot start with a number.

Variable programs in PHP are composed of two parts: code and data. data is stored in variables. the essence of variables is a storage space in memory. Variable corresponding to null...