使用未分配的局部变量

Question

In my code I am getting the following error:

Use of unassigned local variable 'nonrpeatedChar'

Why is this error occurring and how do I fix it?

static void firstNonRepeated(string str)
{
        int i, j, len;
        len = str.Length;

        int count = 1;
        char nonrpeatedChar;
        for (i = 0; i < len; i++)
        {
            for (j = 0; j < len; j++)
            {
                if (i != j && str[i] == str[j])
                {
                    count = count + 1;
                }
            }
            if (count == 1)
            {
                nonrpeatedChar = str[i];
                break;
            }
        }
        Console.WriteLine(nonrpeatedChar);
        Console.ReadLine();
    }           
}

Answer 1

Given your code path, there's no guarantee that nonrepeatedChar has been assigned to before passing it to Console.WriteLine because the only assignment happens inside fo an if block which may or may not be hit.

An easy fix would be to assign a default value when you declare it:

char nonrepeatedChar = default(char);

Answer 2

尝试：

char nonrpeatedChar = new Char();

Answer 3

If str has a len of 0 , the value of nonrpeatedChar is undefined. Therefore Console.WriteLine(nonrpeatedChar); does not work.