public class Student { private String number;//学号 private String name;//姓名 private String sex;//性别 private String class1;//班级 public Student(String number, String name, String sex, String class1) {//有参构造方法 this.number = number; this.name = name; this.sex = sex; this.class1 = class1; } public String getNumber() { return number; } public void setNumber(String number) { this.number = number; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public String getClass1() { return class1; } public void setClass1(String class1) { this.class1 = class1; } public class void main add (String[] args) { Scanner in = new Scanner(System.in); Student[] stu = new Student[100]; int num = 0; while (true) { System.out.println("请输入要执行的操作:"); System.out.println("1.添加学生信息"); System.out.println("2.查看学生信息"); System.out.println("3.退出程序"); int choice = in.nextInt(); if (choice == 1) { if (num > stu.length - 1) { System.out.println("系统成员已满"); continue; } System.out.println("请输入学号"); String number = in.next(); for (int i = 0; i < num; i++) { if (stu[i].getNumber().equals(number)) { System.out.println("学号输入重复,请重新输入"); number = in.next(); i = -1; } } System.out.println("请输入姓名"); String name = in.next(); System.out.println("请输入性别"); String sex = in.next(); System.out.println("请输入班级"); String class1 = in.next(); Student student = new Student(number, name, sex, class1); stu[num] = student; num++; System.out.println("添加成功"); } else if (choice == 2) { if (num == 0) { System.out.println("没有学生信息"); continue; } System.out.println("学号\t姓名\t性别\t班级"); for (int i = 0; i < num; i++) { Student student = stu[i]; System.out.println(student.getNumber() + "\t" + student.getName() + "\t" + student.getSex() + "\t" + student.getClass1()); } } else if (choice == 3) { System.out.println("程序已退出"); break; } else { System.out.println("请输入正确的操作编号"); } } } } }中public class void main add (String[] args) {在jdk进行编译时标识符错误
时间: 2024-03-27 10:35:20 浏览: 10
在Java中,一个类只能有一个main方法,而且其签名必须是:
```
public static void main(String[] args)
```
您的代码中,出现了一个名为add的非法方法签名:
```
public class void main add (String[] args)
```
因此,在编译时出现了标识符错误。正确的写法应该是:
```
public static void main(String[] args)
```
请将您的代码改为以下形式:
```
public class Student {
// 省略其他代码
public static void main(String[] args) {
// 程序逻辑
}
}
```
相关问题
public class Student { private String number;//学号 private String name;//姓名 private String Sex;//性别 private String Class1;//班级 public Student(String number, String name, String Sex,String Class1) {//有参构造方法 this.number =number; this.name = name; this.Sex = sex; this.Class1 = class1; } public String getNumber() { return number; } public void setNumber(String number) { this.number= number; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return Sex; } public void setSex(String Sex) { this.Sex = Sex; } public String getClass1() { return Class1; } public void setClass1(String Class1) { this.Class1 = Class1; } }//添加学生信息的方法 public class void main add (String[] args) if (num > stu.length - 1) { System.out.println("系统成员已满"); return; } Student student = new Student();//创建一个对象,用于接收信息,最后传给数组对象 System.out.println("请输入学号"); String number= in.next(); for (int i = 0; i<num; i++) { while (stu[i].getNumber().equals(number)) { System.out.println("学号输入重复,请重新输入"); number= in.next(); } } student.setNumber(number); System.out.println("请输入姓名"); student.setName(in.next()); System.out.println("请输入性别"); student.setSex(in.next()); System.out.println("请输入班级"); student.setClass1(in.next()); stu[num] = student; num++; System.out.println("添加成功"); } }改错
这段代码存在一些错误,我来帮你找出并改正:
1. `public class void main add (String[] args)` 这一行应该是 `public static void main(String[] args)`,表示这是一个静态的主方法。
2. `if (num > stu.length - 1)`,这里的 `num` 没有定义,应该先定义并初始化为 0。另外,`stu` 数组也没有被定义,需要先定义并初始化。
3. `Student student = new Student();` 这里应该在括号里传入四个参数,分别是学号、姓名、性别和班级。因为 `Student` 类的构造方法需要四个参数。
4. `while (stu[i].getNumber().equals(number))` 这里的 `i` 没有定义,应该使用一个循环来遍历已经添加的学生信息,找出是否已有相同学号的学生。
5. `student.setNumber(number);` 这里应该在输入学号时先判断是否重复,而不是在这里进行判断。
这是修改后的代码:
```
import java.util.Scanner;
public class Student {
private String number;//学号
private String name;//姓名
private String sex;//性别
private String class1;//班级
public Student(String number, String name, String sex, String class1) {//有参构造方法
this.number = number;
this.name = name;
this.sex = sex;
this.class1 = class1;
}
public String getNumber() {
return number;
}
public void setNumber(String number) {
this.number = number;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getClass1() {
return class1;
}
public void setClass1(String class1) {
this.class1 = class1;
}
}
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
Student[] stu = new Student[100];
int num = 0;
while (true) {
System.out.println("请输入要执行的操作:");
System.out.println("1.添加学生信息");
System.out.println("2.查看学生信息");
System.out.println("3.退出程序");
int choice = in.nextInt();
if (choice == 1) {
if (num > stu.length - 1) {
System.out.println("系统成员已满");
continue;
}
System.out.println("请输入学号");
String number = in.next();
for (int i = 0; i < num; i++) {
if (stu[i].getNumber().equals(number)) {
System.out.println("学号输入重复,请重新输入");
number = in.next();
i = -1;
}
}
System.out.println("请输入姓名");
String name = in.next();
System.out.println("请输入性别");
String sex = in.next();
System.out.println("请输入班级");
String class1 = in.next();
Student student = new Student(number, name, sex, class1);
stu[num] = student;
num++;
System.out.println("添加成功");
} else if (choice == 2) {
if (num == 0) {
System.out.println("没有学生信息");
continue;
}
System.out.println("学号\t姓名\t性别\t班级");
for (int i = 0; i < num; i++) {
Student student = stu[i];
System.out.println(student.getNumber() + "\t"
+ student.getName() + "\t"
+ student.getSex() + "\t"
+ student.getClass1());
}
} else if (choice == 3) {
System.out.println("程序已退出");
break;
} else {
System.out.println("请输入正确的操作编号");
}
}
}
}
```
用java完成以下需求 创建一个表示学生的类Student,封装所有属性。包括“姓名(name)”、“学号(studentNum)”、“班级(classNumber)”、“性别(sex)”、“年龄(age)”、 “性格(nature)”,以及所有属性的get、set方法。另加一个重写public String toString()方法把Student类对象的所有属性信息组合成一个字符串,并创建测试类实现该需求。
好的,以下是Java代码实现:
```java
public class Student {
private String name;
private String studentNum;
private String classNumber;
private String sex;
private int age;
private String nature;
public Student(String name, String studentNum, String classNumber, String sex, int age, String nature) {
this.name = name;
this.studentNum = studentNum;
this.classNumber = classNumber;
this.sex = sex;
this.age = age;
this.nature = nature;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getStudentNum() {
return studentNum;
}
public void setStudentNum(String studentNum) {
this.studentNum = studentNum;
}
public String getClassNumber() {
return classNumber;
}
public void setClassNumber(String classNumber) {
this.classNumber = classNumber;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getNature() {
return nature;
}
public void setNature(String nature) {
this.nature = nature;
}
@Override
public String toString() {
return "姓名:" + name +
",学号:" + studentNum +
",班级:" + classNumber +
",性别:" + sex +
",年龄:" + age +
",性格:" + nature;
}
}
```
测试类实现:
```java
public class TestStudent {
public static void main(String[] args) {
Student student = new Student("小明", "20210001", "1班", "男", 18, "开朗");
System.out.println(student.toString());
}
}
```
输出结果为:
```
姓名:小明,学号:20210001,班级:1班,性别:男,年龄:18,性格:开朗
```