Static详细讲解

Static详细讲解

package com.andy.base.oop.demo01.demo07;

import sun.dc.path.PathError;

public class Person {

    //第二输出
    {
        System.out.println("匿名代码块");
    }

    //第一输出     ，只执行一次
    static {
        System.out.println("静态代码块");
    }

    //第三输出
    public   Person(){
        System.out.println("构造方法");
    }

    public static void main(String[] args) {
        Person person1 = new Person();
        System.out.println("==================");
        Person person2 = new Person();
    }
}

package com.andy.base.oop.demo01.demo07;

//static
public class Student  {
    private  static  int age;//静态的变量  多线程！！
    private  double score;   //非静态的变量

    public  void run(){

    }

    public  static  void go(){

    }

    public static void main(String[] args) {
        go();
    }

}

package com.andy.base.oop.demo01.demo07;

//静态导入包~
import static java.lang.Math.random;
import static java.lang.Math.PI;
public class Test {

    public static void main(String[] args) {
       // System.out.println(Math.random());

        System.out.println(random());
        System.out.println(PI);
    }
}