C# Quine Problem | 易学教程

问题

I am trying to understand how this piece of self-replicating code works (found here), but the problem is I can't get it to run as-is:

class c {
    static void Main(){

        string s = "class c{{static void Main(){{string s={0}{10};System.Console.Write(s,(char)34,s);}}}}";

        System.Console.Write(s,(char)34,s); //<<-- exception on this line

    }
}

It's throwing an exception on writeline: Index (zero based) must be greater than or equal to zero and less than the size of the argument list.

Can someone help - in particular about the formatting option {0}{10}?

I got it working like this (see below) but it's longer than the original - I am curious how the original could have worked as-is in the 1st place:

class c {
    static void Main(){

        string s = "class c{{static void Main(){{string s={0}{1}{2};System.Console.Write(s,(char)34,s,(char)34);}}}}";

        System.Console.Write(s,(char)34,s,(char)34);
    }
}

回答1:

I think there is a pair of braces missing - instead of {10} it should read {1}{0}.

class c {
    static void Main(){

        string s = "class c{{static void Main(){{string s={0}{1}{0};System.Console.Write(s,(char)34,s);}}}}";

        System.Console.Write(s,(char)34,s); //<<-- exception on this line

    }
}

回答2:

Could the original work with?

s={0}{1}{0}

回答3:

I believe that the original was supposed to look like this:

class c {
  static void Main() {
    string s = "class c{{static void Main(){{string s={0}{1}{0};System.Console.Write(s,(char)34,s);}}}}";
    System.Console.Write(s, (char)34, s);
  }
}

I.e. the {0}{10} should just be changed to {0}{1}{0}.

The {0} in the format string is used to put the quotation marks before and after the string.

来源：https://stackoverflow.com/questions/1762984/c-sharp-quine-problem

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quine