Question

我正在尝试从Scanner为类对象赋值。我不想使用Teacher a = new Teacher("Ali","SCF333",'M');，因为它已经设置好了，我希望用户输入数据

这是我的驱动程序类：

public class TeacherDriver {
    public static void main(String[]args){


        String data;
        Teacher a = new Teacher();



        Scanner input = new Scanner(System.in);

        System.out.println("Please enter Employee Name: ");
        data=input.nextLine();
        a.setEmpName();
        System.out.println("Please enter Employee ID: ");
        data2=input.nextLine();
        a.setEmpID();
        System.out.println("Please enter Employee Gender: ");
        data3=input.nextLine();
        a.setGender();


        System.out.println(a.toString());


    }
}

这是班级：

public class Teacher {
    private String empID;
    private String empName;
    private Address address;
    private char gender; 
    private String [] Subject;

    Teacher(){

    }

    Teacher(String empName){
        this.empName=empName;
    }

    Teacher(String empName,String empID){
        this.empName=empName;
        this.empID=empID;
    }

    Teacher(String empName,String empID,char gender){
        this.empName=empName;
        this.empID=empID;
        this.gender=gender;
    }

    Teacher(String empName,String empID,char gender,Address address){

        this.empName=empName;
        this.empID=empID;
        this.gender=gender;
        this.address=address;
    }

    Teacher(String empName,String empID,char gender,Address address,String[]Subject){

        this.empName=empName;
        this.empID=empID;
        this.gender=gender;
        this.address=address;
        this.Subject=Subject;   
    }

    public void setEmpID(){
        this.empID=empID;
    }

    public void setEmpName(){
        this.empName=empName;
    }

    public void setGender(){
        this.gender=gender;
    }

    public String getEmpID(){
        return empID;
    }

    public String getEmpName(){
        return empName;
    }

    public char getGender(){
        return gender;
    }

    public Address getAddress(){
        return address;
    }

    public String[] getSubject(){
        return Subject;
    }

     public String toString()
     {
         String viewteacher = new String("Name: " + empName + "\nID: "+ empID +"\nGender: "+ gender + "\nSubjects: "+ Subject); 
          return viewteacher;
     }
}

Answer 1

我不太确定你到底想要什么，但是你走了，

System.out.println("Please enter Employee Name: ");
data=input.nextLine();
a.setEmpName(data);
System.out.println("Please enter Employee ID: ");
data2=input.nextLine();
a.setEmpID(data2);
System.out.println("Please enter Employee Gender: ");
// Assuming that the user is entering correct data
data3=input.nextLine();
a.setGender(data3.charAt(0));

Answer 2

这是创建setter方法的错误方法，这里只是将实例变量empName设置为相同的实例变量empName。

public void setEmpName(){
    this.empName=empName;
}

你必须将参数传递给set方法，然后该参数才会设置。

public void setEmpName(String empName){
    this.empName=empName;
}

TeacherDriver类需要修改如下，

  System.out.println("Please enter Employee Name: ");
  data=input.nextLine();
  a.setEmpName(data);

Answer 3

获取输入后创建对象。

      a.setEmpName();
      a.setEmpID();

以上调用不会设置该值，因为没有任何参数传递给set。修改教师对象创建如下

    Teacher a = new Teacher(data1,data2,data3);

将输入存储在data1，data2和data3变量中后，包括上述调用。

Answer 4

您的setter没有传递任何参数来设置值。以下是他们通常应该看起来的方式

@CacheResult //how to specify the fixed key?
public SystemConfiguration getConfiguration() {
  return configuration; //this is a prebuilt object, as described
}

然后你调用它们：

public void setSomething(String something) {
    this.something=something;
}

您可以查看javadocs了解Scanner的工作原理

如何将一个值从扫描仪分配给对象？

4 个答案: