Java學習筆記-學生管理系統
阿新 • • 發佈:2021-12-14
Java學習筆記
一個Student類
public class Student { private String sid; private String name; private String age; private String address; public Student() { } public Student(String sid, String name, String age, String address) { this.sid = sid; this.name = name; this.age = age; this.address = address; } public String getSid() { return sid; } public void setSid(String sid) { this.sid = sid; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getAge() { return age; } public void setAge(String age) { this.age = age; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } }
一個Student的測試類
import java.util.ArrayList; import java.util.Scanner; public class Student_Demo { public static void main(String[] args) { ArrayList<Student> array = new ArrayList<>(); while (true) { System.out.println("--------歡迎來到學生管理系統--------"); System.out.println("1 新增學生"); System.out.println("2 修改學生"); System.out.println("3 刪除學生"); System.out.println("4 檢視所有學生"); System.out.println("5 退出系統"); System.out.println("請輸入您的選擇:"); Scanner sc = new Scanner(System.in); String line = sc.nextLine(); switch (line) { case "1": // System.out.println("新增學生成功"); addStudent(array); break; case "2": // System.out.println("修改學生成功"); modifyStudent(array); break; case "3": // System.out.println("刪除學生成功"); delStudent(array); break; case "4": // System.out.println("檢視學生成功"); showStudent(array); break; case "5": System.out.println("謝謝使用"); // break; return; // System.exit(0); } } } // 新增學生 // 傳入引數是學生陣列,新增學生物件,不返回 public static void addStudent(ArrayList<Student> array) { Scanner sc = new Scanner(System.in); System.out.println("請輸入學號:"); String sid = sc.nextLine(); boolean flag = false; for (int i = 0; i < array.size(); i++) { if (sid.equals(array.get(i).getSid())) { flag = true; } } if (flag) { System.out.println("有內鬼,停止交易!"); } else { System.out.println("請輸入姓名:"); String name = sc.nextLine(); System.out.println("請輸入年齡:"); String age = sc.nextLine(); System.out.println("請輸入地址:"); String address = sc.nextLine(); Student student = new Student(); student.setSid(sid); student.setName(name); student.setAge(age); student.setAddress(address); array.add(student); System.out.println("新增學生成功!"); } } // 刪除學生 // 傳入的引數是學生陣列,刪除學生物件,不返回 public static void delStudent(ArrayList<Student> array){ Scanner sc = new Scanner(System.in); System.out.println("請輸入您要刪除學生的學號:"); String sid = sc.nextLine(); boolean flag = true; // j用來獲取要刪除物件的索引 int j = 0; for (int i = 0; i < array.size(); i++) { if (sid.equals(array.get(i).getSid())) { flag = false; j = i; } } if(flag){ System.out.println("有內鬼,停止交易!"); }else{ System.out.println("正在刪除........."); array.remove(array.get(j)); } } // 修改學生 // 選擇修改學生的學號,然後可以修改的物件 public static void modifyStudent(ArrayList<Student> array){ Scanner sc = new Scanner(System.in); System.out.println("請輸入您要修改學生的學號:"); String sid = sc.nextLine(); boolean flag = false; int j = 0; for (int i = 0; i < array.size(); i++) { if (sid.equals(array.get(i).getSid())) { flag = true; j = i; } } if(flag){ System.out.println("修改的學號為:"); sid = sc.nextLine(); array.get(j).setSid(sid); System.out.println("修改的姓名為:"); sid = sc.nextLine(); array.get(j).setName(sid); System.out.println("修改的年齡為:"); sid = sc.nextLine(); array.get(j).setAge(sid); System.out.println("修改的地址為:"); sid = sc.nextLine(); array.get(j).setAddress(sid); System.out.println("修改成功,請進行檢視"); }else{ System.out.println("有內鬼,終止交易!"); } } // 檢視所有學生 // 傳入引數是學生陣列,進行遍歷,不返回 public static void showStudent(ArrayList<Student> array) { if (array.size() != 0) { System.out.println("學號\t\t"+"姓名\t\t"+"年齡\t\t"+"地址"); for (int i = 0; i < array.size(); i++) { System.out.printf("%-8s",array.get(i).getSid()); System.out.printf("%-8s",array.get(i).getName()); System.out.printf("%-8s",array.get(i).getAge()); System.out.printf("%-8s",array.get(i).getAddress()); System.out.println(); } System.out.println("檢視完畢"); } else{ System.out.println("請先新增學生,再進行檢視!"); } } }