当我尝试使用方法时它给出错误[关闭]

Question

我有一个switch 语句，我在其中尝试检查string 值，我希望在检查名称后它应该要求标记。但是当我尝试在一个方法中创建 if else 语句时，它会出错。

这是运行良好的代码：

import java.util.Scanner;

public class java {

    public static void main(String args[]) {
        Scanner obj = new Scanner(System.in);
        int num;
        final int pass = 33;
        String Student;
        System.out.println("Please enter your name");
        Student = obj.nextLine();
        switch (Student) {
            case "Ram":
                System.out.println("Students name is " + Student);
                break;
            case "Shyaam":
                System.out.println("Students name is " + Student);
                break;
            default:
                System.out.println("This name is not recognised");

        }

        System.out.println("Enter your marks");
        num = obj.nextInt();
        if (num < pass) {
            System.out.println(Student + " You have failed the subject");
        } else {
            System.out.println(Student + " You have passed the subject");
        }
    }
}

但在这方面，即使名称没有得到验证，它仍然要求标记。

我该怎么办。

请帮忙。

Answer 1

switch 语句不是 while switch 语句。

要允许接受另一个输入，请将switch 包含在while 中，当学生字符串无效时继续。
此外，您应该遵守约定：变量名称应以小写字母开头。
String student 是正确的。 String Student 不是。

 String student = null;

 while (student == null){
    student = obj.nextLine();

    switch(student){
      case "Ram":
        System.out.println("Students name is "+ Student);
        break;
      case "Shyaam":
        System.out.println("Students name is "+ Student);
        break;
      default:
          System.out.println("This name is not recognised");
          student = null;
    }
}

Answer 2

你应该下课了。 在类的末尾添加“}”

Answer 3

您可以将if 条件移动到switch 内部。

switch(Student){
       case "Ram":
       System.out.println("Students name is "+ Student);

       System.out.println("Enter your marks");
       num=obj.nextInt();

       if(num<pass){   
           System.out.println(Student+" You have failed the subject");
       }else{
           System.out.println(Student+" You have passed the subject");
           }

           break;
       case "Shyaam":
       System.out.println("Students name is "+ Student);

       System.out.println("Enter your marks");
       num=obj.nextInt();

       if(num<pass){   
           System.out.println(Student+" You have failed the subject");
       }else{
           System.out.println(Student+" You have passed the subject");
       }
       break;
       default:
           System.out.println("This name is not recognised");
    }

但这会导致您使用更多代码以避免您可以使用更多变量来检查学生姓名是否匹配。为此，您必须使用 boolean 变量。

那么代码应该是：

public static void main(String args[]){
   Scanner obj=new Scanner(System.in);
   int num;
   final int pass=33;

   String Student;
   System.out.println("Please enter your name");
   Student=obj.nextLine();

   boolean isStudent = false;

   switch(Student){
     case "Ram":
         isStudent = true;
       System.out.println("Students name is "+ Student);
       break;
     case "Shyaam":
         isStudent = true;
       System.out.println("Students name is "+ Student);
       break;
     default:
       System.out.println("This name is not recognised");
   } 

   if(isStudent){
       System.out.println("Enter your marks");
       num=obj.nextInt();

       if(num<pass){   
           System.out.println(Student+" You have failed the subject");
       }else{
           System.out.println(Student+" You have passed the subject");
       }
   }else{
       System.out.println("You are not a ....");
   }
}

注意：这是一种方法。