java 父类子类成员变量,静态变量,构造器创建先后顺序

关于java中父类子类,成员变量,静态变量,构造器创建的先后顺序,在面试中经常会问到该类型的问题

所以用以下代码进行测试:

public class Test {
    public static void main(String args[]) {
        Father f = new Son();
    }
}
class Father {
    public Father() {
        System.out.println("Father Construct");
    }
    static int fatherStatic=printFatherStatic();
    int father=printFather();
    static int printFatherStatic() {
        System.out.println("print in father static mamber");
        return 0;
    }
    static int printFather(){
        System.out.println("print in father class mamber");
        return 0;
    }
}
class Son extends Father {
    public Son() {
        System.out.println("Son Construct");
    }
    static int sonStatic=printSonStatic();
    int son=printSon();
    static int printSonStatic() {
        System.out.println("print in son static mamber");
        return 0;
    }
    static int printSon(){
        System.out.println("print in son class mamber");
        return 0;
    }
}

 

运行结果为:

print in father static mamber
print in son static mamber
print in father class mamber
Father Construct
print in son class mamber
Son Construct

 

总结一下,得出以下结论:

创建的先后顺序为:父类的静态变量->子类的静态变量->父类的成员变量->父类的构造方法->子类的成员变量->子类的构造方法

总的来说,首先创建静态方法,然后创建父类的成员变量和构造方法,再创建子类的成员变量和构造方法