Printing Namespace instead of string value

Question

This method supposed to print the following:

Creating r1
-> Assigning r2 to r1
-> Changing values of r2
String = This is new info!, Top = 10, Bottom = 50, Left = 10, Right = 50
String = This is new info!, Top = 10, Bottom = 4444, Left = 10, Right = 50

but instead of printing string value it prints the class in which the string is located

Creating r1
-> Assigning r2 to r1
-> Changing values of r2
String = Csharp_Projects.Program+ShapeInfo, Top = 10, Bottom = 50, Left =  10, Right = 50
String = Csharp_Projects.Program+ShapeInfo, Top = 10, Bottom = 4444, Left = 10, Right = 50

this is the code:

 using System;

 namespace Csharp_Projects
{
  static class Program
{
    static void Main(string[] args)
    {
        ShapeInfo.Rectangle.ValueTypeContainingRefType();
   }

   // this class which takes an string as parameter

    public class ShapeInfo
    {
        public string infoString;

        public ShapeInfo(string info)
        {
            infoString = info;
        }

      // this struct has two fields, one is int type  and the other is ShapeInfo (above) and a constructor which set the values

        public struct Rectangle
        {
            public ShapeInfo rectInfo;

            public int recTop, rectleft, rectBottom, rectRight;

            public Rectangle(string info, int top, int left, int Buttom, int Right)
            {
                rectInfo = new ShapeInfo(info);
                recTop = top;
                rectBottom = Buttom;
                rectRight = Right;
                rectleft = left;
            }
            // this method print the results
            public void Display()
            {
                Console.WriteLine("string={0},top={1},Bottom={2},"+"left={3},Right={4}",rectInfo,recTop,rectBottom,rectRight,rectleft);
            }

            // this method make an object and assign it to second variable and then change the values of second variable .

            public static void ValueTypeContainingRefType()
            {
                Console.WriteLine("Creating r1");
                Rectangle r1 = new Rectangle("First Rec", 10, 10, 50, 50);
                Console.WriteLine("Assigning r2 to r1");
                Rectangle r2 = r1;
                Console.WriteLine("Change Values of r2");
                r2.rectInfo.infoString = "This is new info!";
                r2.rectBottom = 4444;
                r1.Display();
                r2.Display();
            }


        }
    }
}
  }

I really couldn't make out why it happened maybe my knowledge about C# system is not enough, what cause this?

David · Accepted Answer · 2017-01-24 18:19:19Z

2

You don't override .ToString() in your ShapeInfo class, so the system has no way of knowing how you want to print an instance of that class as a string. By default all objects print their class name (since that's pretty much the only thing every class is guaranteed to have).

Just override the method:

public override string ToString()
{
    return infoString;
}

answered Jan 24, 2017 at 18:19

David

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3 Comments

Mohsen Over a year ago

which method should take override? because it gives me an error . and btw I inserted the code from very famous book why it didn't mention it there? I mean he got the first print without using override

David Over a year ago

@Mohsen: I can't really help with an error you haven't described. As for your "very famous book", I also can't comment on code I haven't seen.

Mohsen Over a year ago

thanks anyway for your time. it seems I should study the override concept.

Kevin Kunderman · Accepted Answer · 2017-01-24 18:22:06Z

1

You need to override the ToString method in ShapeInfo to return the infoString.

public override string ToString()
{
    return infoString;
}

Or change the your DisplayMethod to use rectInfo.infoString instead of rectInfo

        public void Display()
        {
            Console.WriteLine("string={0},top={1},Bottom={2},"+"left={3},Right={4}",rectInfo.infoString,recTop,rectBottom,rectRight,rectleft);
        }

answered Jan 24, 2017 at 18:22

Kevin Kunderman

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1 Comment

Mohsen Over a year ago

Thanks, I notice now that in the book in mentioned your second solution, I just forgot infoString. oh... it was not that hard then

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