java中static方法的继承性

首先需要知道的是,java中所有的public实例方法都默认是virtual的,static方法不是virtual的,所以static方法可以被覆盖(new),但不可被重写(override)

1.被继承

父类:

public class Parents{
    public static void staticFunction(){
        System.out.println("public static function of parents");
    }
    public void callPrintName(){
        this.printName();
    }    
}

子类:

 

1 public class Child extends Parents{
2     public static void main(String[] args){
3         Child child=new Child();
4         child.staticFunction();
5     }
6     
7 }

输出

public static function of parents

说明static方法可以被继承

 

2.被覆盖(new)

父类:

public class Parents{
    public static void staticFunction(){
        System.out.println("public static function of parents");
    }
    public void callPrintName(){
        this.printName();
    }    
}

子类:

public class Child extends Parents{
    public static void staticFunction(){
        System.out.println("public static function of Child");
    }
    public static void main(String[] args){
        Child child=new Child();
        child.staticFunction();
    }
    
}

 

输出:

public static function of Child

上面输出是public static function of Child,说明static已经被覆盖(new)了

3.不是virtual,即不能实重写(override)

//父类
public class Parents{
    private void printName(){
        System.out.println("private function of parents");
    }
    public static void staticFunction(){
        System.out.println("public static function of parents");
    }
    public void callPrintName(){
        this.printName();
    }    
}





//子类
public class Child extends Parents{
    public static void staticFunction(){
        System.out.println("public static function of Child");
    }
    public static void main(String[] args){
        Parents child=new Child();
        child.staticFunction();
    }
    
}

输出:

public static function of parents

 上面的child是属于Child实例,用Parents引用,输出的是public static function of parents,说明static方法不是virtual的,不能被重写(override)。



posted on 2017-09-13 16:46  J.M.Liu  阅读(4149)  评论(3编辑  收藏  举报