类的继承

1.子类覆盖父类的成员变量

class A{
    String name = "tom";
    A(String name){
        this.name = name;
    }
}

class B extends A{
    String name = "jack";
    B(String name){
        super(name);
    }
}

public class BigInt {
    public static void main(String[] args) {
        B b = new B("helen");
        System.out.println(b.name);
    }
}

运行结果：

jack

 

---------------------------------------------------------------------------------------------------------------------------------------

class A{
    String name = "tom";
    A(String name){
        this.name = name;
    }
}

class B extends A{
    String name = "jack";
    B(String name){
        super(name);
    }
}

public class BigInt {
    public static void main(String[] args) {
        A b = new B("helen");
        System.out.println(b.name);
    }
}

运行结果：

helen

 

---------------------------------------------------------------------------------------------------------------------------------------

class A{
    String name = "tom";
    A(String name){
        this.name = name;
    }
}

class B extends A{
    String name = "jack";
    B(String name){
        super(name);
        this.name = name;
    }
}

public class BigInt {
    public static void main(String[] args) {
        A b = new B("helen");
        System.out.println(b.name);
    }
}

运行结果：

helen

 

---------------------------------------------------------------------------------------------------------------------------------------

class A{
    String name = "tom";
    A(String name){
        this.name = name;
    }
}

class B extends A{
    String name = "jack";
    B(String name){
        super(name);
        this.name = name;
    }
}

public class BigInt {
    public static void main(String[] args) {
        B b = new B("helen");
        System.out.println(b.name);
    }
}

运行结果：

helen