題目：

程式碼：

  1 package org.wlgzs;
  2 
  3 import java.util.ArrayList;
  4 import java.util.List;
  5 import java.util.Scanner;
  6 
  7 /**
  8  * @author zsh
  9  * @company wlgzs
 10  * @create 2018-11-27 21:42
 11  * @Describe：用集合實現學生的增刪查改
 12  */
 13 public class SimpleStudentManage {
 14
 
     public static List<Student> allStudent = new ArrayList<>();
 15 
 16     //初始化資料用
 17     static {
 18         allStudent.add(new Student("001","1號","男",20,161));
 19         allStudent.add(new Student("002","2號","女",21,171));
 20         allStudent.add(new Student("003","3號","男",22,181));
 21
 
     }
 22 
 23     //判斷密碼
 24     public boolean login(String password){
 25         if (password.equals("123456")){
 26             return true;
 27         }else {
 28             return false;
 29         }
 30     }
 31 
 32     //查詢所有
 33     public void findAll(){
 34         for (Student s :allStudent){
 
 35             System.out.println(s);
 36         }
 37     }
 38 
 39     //增加學生
 40     public boolean addStudent(Student student){
 41         return allStudent.add(student);
 42     }
 43 
 44     //刪除學生
 45     public boolean deleteStudent(String number){
 46         for (int i = 0;i<allStudent.size();i++){
 47             if (allStudent.get(i).getNumber().equals(number)){
 48                 return allStudent.remove(allStudent.get(i));
 49             }
 50         }
 51         return false;
 52     }
 53 
 54     public static void main(String[] args) {
 55         Scanner scanner = new Scanner(System.in);
 56         //判斷密碼
 57         System.out.println("請輸入密碼");
 58         SimpleStudentManage simpleStudentManage = new SimpleStudentManage();
 59         if (simpleStudentManage.login(scanner.nextLine())){
 60             System.out.println("------列印所有--------");
 61             simpleStudentManage.findAll();
 62             System.out.println("----------------------");
 63             //建立兩個學生物件
 64             Student s1 = new Student("004","4號","男",23,191);
 65             //加入list集合
 66             if (simpleStudentManage.addStudent(s1)){
 67                 System.out.println("新增成功");
 68             }else {
 69                 System.out.println("新增失敗");
 70             }
 71             System.out.println("------列印所有--------");
 72             simpleStudentManage.findAll();
 73             System.out.println("----------------------");
 74             //刪除
 75             System.out.println("請輸入刪除學號");
 76             if (simpleStudentManage.deleteStudent(scanner.nextLine())){
 77                 System.out.println("刪除成功");
 78             }else {
 79                 System.out.println("刪除失敗");
 80             }
 81             System.out.println("------列印所有--------");
 82             simpleStudentManage.findAll();
 83             System.out.println("----------------------");
 84         }
 85     }
 86 }
 87 
 88 //學生類
 89 class Student{
 90     private String number;  //學號
 91     private String name;  //名字
 92     private String sex;  //性別
 93     private int age;  //年齡
 94     private int grade;  //班級
 95 
 96     //有參構造器
 97     public Student(String number, String name, String sex, int age, int grade) {
 98         this.number = number;
 99         this.name = name;
100         this.sex = sex;
101         this.age = age;
102         this.grade = grade;
103     }
104 
105     //無參構造器
106     public Student() {
107     }
108 
109     //get,set方法
110     public String getNumber() {
111         return number;
112     }
113 
114     public void setNumber(String number) {
115         this.number = number;
116     }
117 
118     public String getName() {
119         return name;
120     }
121 
122     public void setName(String name) {
123         this.name = name;
124     }
125 
126     public String getSex() {
127         return sex;
128     }
129 
130     public void setSex(String sex) {
131         this.sex = sex;
132     }
133 
134     public int getAge() {
135         return age;
136     }
137 
138     public void setAge(int age) {
139         this.age = age;
140     }
141 
142     public int getGrade() {
143         return grade;
144     }
145 
146     public void setGrade(int grade) {
147         this.grade = grade;
148     }
149 
150     //重寫toString
151     @Override
152     public String toString() {
153         return "Student{" +
154                 "number='" + number + '\'' +
155                 ", name='" + name + '\'' +
156                 ", sex='" + sex + '\'' +
157                 ", age=" + age +
158                 ", grade=" + grade +
159                 '}';
160     }
161 }