Basic usage of static variables in php

Static variables only exist in the function scope, and static variables only exist in the stack. The next time you call this function, the value of this variable is retained. the static variable only exists in the function scope, and the static variable only exists in the stack. Generally, variables in a function are released after the function ends, such as local variables, but static variables do not. The value of this variable is retained the next time you call this function.

Basic usage of static variables

1. define static variables in the class
[Access modifier] static $ variable name;
2. how to access static variables
If there are two methods to access a class: self: $ static variable name, class name: $ static variable name
For out-of-class access: there is a method class name: $ static variable name

Example

The code is as follows:

Class Child {

Public $ name;
// Define and initialize a static variable $ nums
Public static $ nums = 0;
Function _ construct ($ name ){

$ This-> name = $ name;
}

Public function join_game (){

// Self: $ nums use static variables
Self: $ nums + = 1;

Echo $ this-> name. "joining snowman game ";

}


}

// Create three children

$ Child1 = new Child ("Li Yun ");
$ Child1-> join_game ();
$ Child2 = new Child ("Zhang Fei ");
$ Child2-> join_game ();
$ Child3 = new Child ("Tang Seng ");
$ Child3-> join_game ();

// Check the number of people playing games
Echo"
There is this ". Child: $ nums;