java继承顺序,和构造函数执行顺序

父类

public class People {
    private String name;
    private static People people = new People();
    private static int n = 10;
    private int age = setAge();

    {
        System.out.println("初始化块");
        System.out.println("age = " + age);
    }

    static {
        System.out.println("静态块");
        System.out.println("n = " + n);

    }

    public static int setAge() {
        return n++;
    }
    public People() {
        System.out.println("默认构造函数");
        System.out.println("age:" + age);
    }
    public People(String name, int age) {
        this.name = name;
        this.age = age;
        System.out.println("有参构造函数");
        System.out.println("age:" + age);
    }
    {
        System.out.println("初始化块1");
        System.out.println("age = " + age);
    }
}

子类

	public  class Student  extends People {

    private  static  int num=20;
    private  String school;
    {
        System.out.println("student 初始化块");
        school="河北小学";
        System.out.println(school);
    }
    static {
        System.out.println("student 静态块");
    }
    public Student() {
    }
    public Student(String name, int age) {
        super(name, age);
        System.out.println("student 构造函數");
    }
}

主函数

import java.util.*;

public class Main {

    public static void main(String[] args) {
        Student p = new Student();
        Student p1=new Student("zhangsan",40);   }
}

结果:初始化块
age = 0
初始化块1
age = 0
默认构造函数
age:0
静态块
n = 10
student 静态块
初始化块
age = 10
初始化块1
age = 10
默认构造函数
age:10
student 初始化块
河北小学
初始化块
age = 11
初始化块1
age = 11
有参构造函数
age:40
student 初始化块
河北小学
student 构造函數

结论

从上到下执行父类静态变量;然后遍历所有的非静态变量进行初始化
父类的静态代码块
子类的静态代码块
然后执行主程序
如果在父类或者子类有调用构造函数的new对象先执行