Java 中变量初始化子类和父类构造器调用的顺序

Posted 2020-12-31 arthurren

先说结论

变量初始化 -> 父类构造器 -> 子类构造器

贴代码

Animcal.java 父类

public class Animal
{
    private static int index = 0;

    private static String getStaticName()
    {
        String name = String.format("animal %d" , index++);
        System.out.println(name);
        return name;
    }

    private String name = getStaticName();

    public Animal()
    {
        System.out.println("create animal");
    }
}

Cat.java 子类

public class Cat extends Animal
{
    public Cat()
    {
        System.out.println("create cat");
    }
}

Main.java

public class Main {
    public static void main(String[] args) throws Exception
    {
        Cat cat = new Cat();
    }
}

打印结果

animal 0
create animal
create cat