Java编程练习题：面向对象入门

练习题：面向对象入门"/>

Java编程练习题：面向对象入门

目录

1. Stack类的实现

2. 定义一个Admin类，该类存在，username、password属性，实现一个控制台版的用户注册登录

3. 定义一个猫类（Cat），该猫有名字、性别、年龄、主人、皮毛

4. class57. MyInteger类（类与对象，构造函数）

5. Class58.自定义String类（类与对象，构造函数）

1. Stack类的实现

根据类图，实现Stack类

import java.util.Arrays;public class Stack {public int capacity = 10; // 容量public int[] data = new int[capacity]; // 数据public int top = 0; public Stack() {}public Stack(int capacity) {this.capacity = capacity;}public void push(int e) {if (capacity == top) {System.out.println("栈满了！");// 抛出栈溢出异常}else {data[top++] = e;}}public int pop() {if (isEmpty()) {return -1;}else {return data[--top];}}public int peek() {if (isEmpty()) {return -1;}else {return data[top - 1];}}public boolean isEmpty() {if (top == 0) {return true;}else {return false;}}public void clear() {top = 0;}public int size() {return top;}@Overridepublic String toString() {return "Stack [data=" + Arrays.toString(data) + ", top=" + top + ", capacity=" + capacity + "]";}public static void main(String[] args) {Stack stack = new Stack();stack.push(11);stack.push(22);stack.push(33);stack.push(44);stack.push(55);System.out.println(stack);System.out.println(stack.peek()); // 5stack.push(66);System.out.println(stack.isEmpty()); // falseSystem.out.println(stack);System.out.println(stack.pop()); // 66System.out.println(stack.size()); // 5stack.clear();System.out.println(stack.isEmpty()); // trueSystem.out.println(stack);}
}

结果：

2. 定义一个Admin类，该类存在，username、password属性，实现一个控制台版的用户注册登录

案例：将注册的用户写在一个数组中。

import java.util.Arrays;
import java.util.Scanner;/** 定义一个Admin类，该类存在，username、password属性，实现一个控制台版的用户注册登* 案例：将注册的用户写在一个数组中。*/
public class Admin {public String username;public String passwd;public Admin() {super();}public Admin(String username, String passwd) {super();this.username = username;this.passwd = passwd;}@Overridepublic String toString() {return "Admin [username=" + username + ", passwd=" + passwd + "]";}public static void main(String[] args) {Scanner scanner = new Scanner(System.in);Admin[] userArr = new Admin[10];System.out.println("请先注册账号！");System.out.println("请输入用户名：");String username = scanner.next();System.out.println("请输入密码：");String passwd = scanner.next();Admin admin = new Admin(username, passwd);System.out.println(admin);for (int i = 0; i < userArr.length; i++) {if (userArr[i] == null) {userArr[i] = admin;break;}}System.out.println(Arrays.toString(userArr));System.out.println("请登录账号！");System.out.println("请输入用户名：");String uname = scanner.next();System.out.println("请输入密码：");String pword = scanner.next();if (admin.username.equals(uname) && admin.passwd.equals(pword)) {System.out.println(admin.username + ",登录成功！");}else {System.out.println("用户名或密码不匹配！");}scanner.close();}
}

结果：

3. 定义一个猫类（Cat），该猫有名字、性别、年龄、主人、皮毛

package com.openlab.day11.exer;
/** 定义一个猫类（Cat），该猫有名字、性别、年龄、主人、皮毛*/
public class Cat {public String name;public boolean gender;public int age;public String master;public String color;public Cat(String name, boolean gender, int age, String master, String color) {super();this.name = name;this.gender = gender;this.age = age;this.master = master;this.color = color;}public Cat() {super();}@Overridepublic String toString() {return "Cat [name=" + name + ", gender=" + gender + ", age=" + age + ", master=" + master + ", color=" + color+ "]";}public static void main(String[] args) {Cat cat = new Cat("小汪", false, 12, "小明", "橘色");System.out.println(cat);Cat cat1 = new Cat();cat1.name = "小喵";cat1.gender = true;cat1.age = 10;cat1.master = "小强";cat1.color = "银渐层";System.out.println(cat1);}
}

结果：

4. class57. MyInteger类（类与对象，构造函数）

import java.util.Scanner;
/** MyInteger类（类与对象，构造函数）*/
public class MyInteger {public int a;public MyInteger() {}public MyInteger(int x) {this.a = x;}public boolean isEven() {if (a % 2 == 0)return true;elsereturn false;}public boolean isOdd() {if (a % 2 != 0)return true;elsereturn false;}public boolean isPrime() {int i, k = 0;if (a == 2)return true;for (i = 2; i < a; i++) {if (a % i == 0)k = 1;}if (k == 0)return true;elsereturn false;}public boolean equals(MyInteger a) {if (this.a == a.a)return true;elsereturn false;}public boolean equals(int a) {if (this.a == a)return true;elsereturn false;}public static void main(String[] args) {Scanner input = new Scanner(System.in);int x = input.nextInt();int y = input.nextInt();int z = input.nextInt();input.close();MyInteger A = new MyInteger(x);MyInteger B = new MyInteger(y);MyInteger C = new MyInteger();System.out.println(C);System.out.println(A.isEven());System.out.println(A.isOdd());System.out.println(A.isPrime());System.out.println(A.equals(z));System.out.println(A.equals(B));}
}

结果：

5. Class58.自定义String类（类与对象，构造函数）

暂时没写