[java]构造函数的继承执行顺序

2014-11-24 09:19:19 · 作者: · 浏览: 1

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

[java]
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