下列程序中注释的哪两个代码(A,B,C,D)是错误的(无法通过编译)? class Father{ private int money=12; float height; int seeMoney(){ return money; //A } } class Son extends Father{ int height; int lookMoney(){ int m=seeMoney(); //B return m; } } class E{ public static void main(String args[]){ Son erzi=new Son(); erzi.money=300; //C erzi.height=1.78F; //D } }
【单选题】若有以下程序代码 class Father{public void show(){}} class Son extends Father{ public void show(){} public void print(){} } class Main{ public static void main(String []s){ Father f; // ① f=new Father(); //② f.show(); // ③ f = new Son(); //④ f.show(); //⑤ f.print(); //⑥ } 则能实现多态的语句组合是()
【填空题】读下面程序,写出程序运行结果。 class Father { int num1=0; public Father(){ System.out.println("num1:"+num1);} public Father(int num1){ this.num1=num1; System.out.println("num1:"+num1); } } class Son extends Father{ int num2=10; public Son(){System.out.println("num2:"+num2);} public Son(int i,int j){ super(i); num2=j; System.out.println("num1:"+num1+",num2:"+num2); } } public class Demo{ public static void main(String []args){ Father father=new Father(); S