C# 未分配的局部变量？

Question

如何修复错误：成绩 "unassigned local variable"？我尝试在 'string' 之前使用 public 和私有前缀，但没有用。有人可以解释一下 private 和 public 的作用吗？谢谢

using System;

public class Program
{
    public static void Main()
    {
        bool answered = false;
        string grade;

        while(answered == false)
        {
            Console.Write("What is your mark? ");
            int mark = Convert.ToInt16(Console.ReadLine());
            answered = true;        

            if(mark >= 90 && mark <= 100)
            {
                grade = "A";

            } else if(mark >= 80 && mark < 90)
            {
                grade = "B";

            } else if(mark >= 55 && mark < 80)
            {
                grade = "C";

            } else if(mark >= 40 && mark < 55)
            {
                grade = "D";

            } else if(mark >= 0 && mark < 40)
            {
                grade = "E";

            } else
            {
                Console.WriteLine("Please enter your mark between 0-100");
                answered = false;
            }
                Console.WriteLine("Your grade is a " + grade);
                Console.ReadLine();
        }

    }
}

Answer 1

您需要确保在所有情况下都为 grade 分配了一个值，以便它始终具有一个值。您可以先用一个值初始化它：

string grade = "";

或者，在您的所有条件下将其设置为一个值，这意味着在您的其他条件中设置它：

 else
 {
    Console.WriteLine("Please enter your mark between 0-100");   
    grade = "";
 }

C# 未分配的局部变量？

C# Unassigned local variable?

c#

windows

console

console-application