问个简单的问题,初学.

Question

using System;
using System.Collections.Generic;
using System.Text;namespace ConsoleApplication2
{
     enum orientatiton:byte
        {
            north =1,
            south=2,
            east=3,
            west=4        }        struct route
        {
            public orientatiton direction;
            public double distance;        }
    class Program
    {
        static void Main(string[] args)
        {
            route myRoute;
            int myDirection = -1;
            double myDistance;
            Console.WriteLine("1) North\n 2) South\n 3) East\n 4) West");
            do
            {
                Console.WriteLine("Select a direction:");
                myDirection = Convert.ToInt32(Console.ReadLine());
            }
            while ((myDirection < 1) || (myDirection > 4));
            Console.WriteLine("Input a distance:");
            myRoute.direction = (orientatiton)myDirection;
            myRoute.distance = myDistance;
            Console.WriteLine("myRoute specifies a direction of {0} and a " + "distance of {1}", myRoute.direction, myRoute.distance);
            Console.ReadKey();
        }
    }
    
}
错误提示使用了未赋值的局部变量 myDistance

Answer 1

double myDistance;   中间没赋值myRoute.distance = myDistance;

Answer 2

double myDistance = 0.0;

Answer 3

 double myDistance;
==
 double myDistance = 0;