Question

public class Student{

    String name;
    double cgpa;
    String status;

    public void setName(String name){

        this.name=name;
    }

    public String getName(){

        return name;
    }
    public void setCgpa(double cgpa){

        this.cgpa=cgpa;
    }

    public double getCgpa(){
        return cgpa;
    }

    public String findStatus(){


        if(cgpa >= 2.0){
            System.out.println("Your Status : Good Standing (GS)");
        } else if (cgpa >1.7){
            System.out.println("Your Status: Probational (P)");
        } else{
            System.out.println("Your Status: Fail (F)");
        }
        return status;
    }

    public String toString() {

        return "\nStudent Name: "+name+"\nYour current status: "+status;
    }

    public static void main(String[]args){

        Scanner in = new Scanner(System.in);
        System.out.println("Please enter your name: ");
        String name=in.nextLine();
        System.out.println("Please enter your CGPA: ");
        double cgpa=in.nextDouble();

        Student mystudent = new Student();
        System.out.println("Your name: " +mystudent.getName());
        System.out.println("Your CGPA: " +mystudent.findStatus());

    }       
}

以下代码没有任何语法错误，但是当我尝试执行它时，用户输入不存储，因此输出变为null。我尝试在TestStudent类中创建运行它，但结果仍然相同。

Answer 1

下面的代码不会存储您的信息，因为您没有保存它。

Student mystudent = new Student();
System.out.println("Your name: " +mystudent.getName());
System.out.println("Your CGPA: " +mystudent.findStatus());

使用以下代码执行此操作：

Student mystudent = new Student();
mystudent.setName(name);
mystudent.setCgpa(cgpa);

// now it will give you the result
System.out.println("Your name: " +mystudent.getName());
System.out.println("Your CGPA: " +mystudent.findStatus());

Answer 2

你忘了存储数据：

您需要添加以下行：

 mystudent.setName(name);
 mystudent.setCgpa(cgpa);

它看起来像这样。

public static void main(String[]args){
    Student mystudent = new Student();

    Scanner in = new Scanner(System.in);

    System.out.println("Please enter your name: ");
    String name=in.nextLine();
    mystudent.setName(name);

    System.out.println("Please enter your CGPA: ");
    double cgpa=in.nextDouble();
    mystudent.setCgpa(cgpa); 


    System.out.println("Your name: " +mystudent.getName());
    System.out.println("Your CGPA: " +mystudent.findStatus());

}

Answer 3

此代码中有两个不好的实现。你的findStatus（）返回了空（未初始化）字符串，你没有设置（初始化）名称和 cgpa 这是编辑过的代码

公共班学生{

字符串名称;双cgpa;字符串状态;

public void setName（String name）{

this.name=name; }

public String getName（）{

return name; } public void setCgpa(double cgpa){

this.cgpa=cgpa; }

public double getCgpa（）{ 返回cgpa; }

public String findStatus（）{

if(cgpa >= 2.0){
    status = "Status : Good Standing (GS)";
} else if (cgpa > 1.7){
     status = "Your Status: Probational (P)";
} else{
     status = "Status: Fail (F)";
}
return status;
} public String toString(){
  return "\nStudent Name: "+name+"\nYour current status: "+status;    }

public static void main(String[]args){

学生mystudent =新学生（）;

Scanner in = new Scanner(System.in);
System.out.print("Please enter your name: ");
String name=in.nextLine();
mystudent.setName(name);

System.out.print("Please enter your CGPA: ");
double cgpa=in.nextDouble();
mystudent.setCgpa(cgpa);

System.out.println("Your name: " +mystudent.getName());
System.out.println("Your CGPA: " +mystudent.findStatus());

}}

Java - 用户输入不存储

3 个答案: