【java】构造函数的继承执行顺序 博客分类： java知识总结 java

问题：

子类继承父类，构造函数及公共属性的执行顺序是怎样的？

示例代码

 

public class A extends C {
	B b = new B();
	static H h = new H();
	static {
		System.out.println("this is static tack");
	}

	static void i() {
		System.out.println("this is static metod");
	}

	public A() {
		System.out.println("this is class A");

	}

	public static void main(String[] args) {
		A a = new A();
	}
}

class B {
	public B() {
		System.out.println("this is class B");
	}
}

class C {
	D d = new D();
	static E e = new E();
	final F e1 = new F();
	static final G e2 = new G();

	public C() {
		System.out.println("this is class C");
	}
}

class D {
	public D() {
		System.out.println("this is class D");
	}
}

class E {
	public E() {
		System.out.println("this is class E");
	}
}

class F {
	public F() {
		System.out.println("this is class F");
	}
}

class G {
	public G() {
		System.out.println("this is class G");
	}
}

class H {
	public H() {
		System.out.println("this is class H");
	}
}

执行结果：

this is class E
this is class G
this is class H
this is static tack
this is class D
this is class F
this is class C
this is class B
this is class A

执行顺序：

1、实现父类公共的静态属性或静态的块级代码

2、实现本身的公共的静态属性

3、实现父类公共属性

4、执行父类的构造方法

5、实现本身的公共属性

6、执行本身的构造函数

7、静态方法不执行

补充：

当父类有多个构造函数，若子类用super(参数信息)指明调用父类有参数的构造函数，则不执行无参数的构造方法