使用类和构造函数读取名称和值

如何解决使用类和构造函数读取名称和值

我想知道学校有多少学生，并使用类和构造函数一一读取这些学生的姓名和成绩。然后，显示学校的成绩表。

例如学校有 5 个学生，我输入

• “约翰”“85”

• “迈克尔”“59”

• “罗伯特”“64”

• “简”“100”

• “托尼”“42”

然后我想让程序显示这张表

• 0-39：
• 40-69:***
• 70-89:*
• 90-100：*

这是小代码和设计。 （这不是考试题或作业，我是 C# 新手，只是想解决一些问题。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace csharcpconsole
{
   
    class Program
    {
        class Student
        {
            public string name;
            public int grade;

            public Student(string studentname,int studentgrade)
            {
                name = studentname;
                grade = studentgrade;
            }

        }

        static void Main ()
        {
            Console.WriteLine("How many student you will add?");
            int studentcount = int.Parse(Console.ReadLine());

            for(int i=0;i<studentcount;i++)
            {
                Console.WriteLine($"Please enter the {i + 1}'th student name.");
               Student  st = new Student (Console.ReadLine())

                Console.WriteLine($"Please enter the {i + 1}'th student name and grade.");
                Student st = new Student int.Parse(Console.ReadLine())
            }


        }

       

       
    }
}

解决方法

1. 我会将您的 Student 类更改为使用自动属性

2. 使用 List<T> 来存储创建的每个新学生

3. 打印到控制台并使用 Linq 获取年级范围内的学生人数

   public class Student
   {
       public string Name { get; set;} //auto property
       public int Grade { get; set; } //auto property
   }
   
   static void Main ()
   {
       Console.WriteLine("How many student will you add?");
       string consoleInput = Console.ReadLine();
       //int for out parameter of int.TryParse()
       int outInt = default(int); //Or in C# 9 - int outInt = default;
       int studentcount = Int32.TryParse(consoleInput,out outInt) ? 
                            outInt : 0; // Or throw an exception??
       //initialize a List<T> of Student type
       List<Student> students = new List<Student>(studentcount);
   
       for(int i=0;i<studentcount;i++)
       {               
          Console.WriteLine($"Please enter the {i + 1}'th student name.");
          Student st = new Student { Name = Console.ReadLine() };
   
          Console.WriteLine($"Please enter the {i + 1}'th student name and grade.");
          //You don't need to create another Student,use the one from above
          //re-use the string from above
          consoleInput = Console.ReadLine();
          st.Grade = Int32.TryParse(consoleInput,out outInt) ? 
                         outInt : 0; //Or throw exception??
   
          //Add your student to the list
          students.Add(st);
       }
   
       //Print the result to the console
       if(students.Count > 0)
       {
           //Get students 0-39
           int number = students.Where(z => z.Grade < 40).Count();
           Console.WriteLine("0-39: " + ReturnAsteriks(number));
           //students 40-69
           number = students.Where(z => z.Grade >= 40 && z.Grade < 70).Count();
           Console.WriteLine("40-69: " + ReturnAsteriks(number));
           //students 70-89
           number = students.Where(z => z.Grade >= 70 && z.Grade < 90).Count();
           Console.WriteLine("70-89: " + ReturnAsteriks(number));
           //students 90-100
           number = students.Where(z => z.Grade >= 90).Count();
           Console.WriteLine("90-100: " + ReturnAsteriks(number));
       }
   }
   
   //Private method to build the number of asteriks
   //Takes an int and returns a string of asteriks
   private string ReturnAsteriks(int numOfAsteriks)
   {
       StringBuilder sb = new StringBuilder("");
       for(int z = 0; z < numOfAsteriks; z++)
       {
           sb.Append("*");
       }
   
       return sb.ToString();
   }