题目内容

关于接口声明的语法,以下说法正确的是

A. 接口中的数据成员一定要有初值,且此值不能再更改,final关键词不可省略
B. 接口中的方法必须是“抽象方法”,不能有方法体,可以省略public及abstract关键字
C. 接口中的数据成员可以有变量,可以有常量。
D. 只有接口中可以有抽象方法

查看答案

搜索结果不匹配？点我反馈

更多问题

如果想要文字量的的实际内容是 “I’m very interested in java Programming” (包含””),以下文字量声明正确的是:

A. string str = “I’m very interested in java Programming”
B. string str = \“I\’m very interested in java Programming\”
C. string str = “\“I\’m very interested in java Programming\””
D. string str = “I\’m very interested in java Programming”

查看答案

给定java代码如下所示,在A处新增下列( )方法,是对cal方法的重载 public class Test { public void cal(int x, int y, int z) { } //A }

A. public int cal(int x,int y,float z){return 0;}
B. public int cal(int x,int y,int z){return 0;}
C. public void cal2(int x, int y, int z){}
D. public viod cal(int z,int y,int x){}

查看答案

下面关于抽象类和抽象方法的说法中,错误的是

A. 抽象类可以包含非抽象方法
B. 抽象类可以定义对象
C. 抽象类可以包含抽象方法
D. 抽象类不可以被实例化

查看答案

import java.io.*;class Person{public void print(){System.out.print("Person ");}public void printMyGender(String s){this.print();System.out.print(s+" ");}}class Gender{String type="gender";public void print(Person p){p.printMyGender(type);}}class Female extends Gender{public Female(){type="female";}}class Male extends Gender{public Male(){type="male";}}class Employee extends Person{public void print(){System.out.print("Employee ");}}class Manager extends Employee{public void print(){System.out.print("Manager ");}}public class Test{public static void main(String[] args){Manager man = new Manager();Employee em = new Employee();Gender gender1 = new Male();Gender gender2 = new Female();gender1.print(man);gender2.print(em);}}对于以上代码,其运行结果是

A. Person male Person female
B. Person gender Person gender
C. Manager male Employee female
D. Manager gender Employee gender

查看答案