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C# Intermediate C# System.Object Object.Equals

vincent batteast
vincent batteast
51,094 Points
Posted by vincent batteast
vincent batteast
51,094 Points

Add an Equals method to the VocabularyWord class that returns true if the words of two VocabularyWord objects are the sa

VocabularyWord.cs(4,18): warning CS0659: Treehouse.CodeChallenges.VocabularyWord' overrides Object.Equals(object) but does not override Object.GetHashCode() VocabularyWord.cs(20,34): error CS0118:Treehouse.CodeChallenges.VocabularyWord' is a type' but avariable' was expected VocabularyWord.cs(20,34): error CS0119: Expression denotes a type', where avariable', value' ormethod group' was expected Compilation failed: 2 error(s), 1 warnings

VocabularyWord.cs 
using System;
namespace Treehouse.CodeChallenges
{
    public class VocabularyWord
    {
        public string Word { get; private set; }

        public VocabularyWord(string word)
        {
            Word = word;
        }

        public override string ToString()
        {
            return Word;
        }

        public override bool Equals(object word)
    {
        if (Word.Equals(word) && VocabularyWord != null )
        {
            return false;
        }
        else 
        {
            return true;   
        }
    }
    }
}

8 Answers

Steven Parker
Steven Parker
231,198 Points
Steven Parker
Steven Parker
231,198 Points

It looks like you missed my first hint last time.

I'll repeat it for you in this batch:

  • if (!(obj is Word)) :point_left: "Word" is not a type (but "VocabularyWord" would be!)
  • that.Equals(Word) :point_left: "that" is the whole object — but that.Word is the string

And you almost got the formatting, but instead of 3 apostrophes ( ' ), you need 3 accents ( ` ).

Steven Parker
Steven Parker
231,198 Points
Steven Parker
Steven Parker
231,198 Points

In my hints I gave you direct substitutions for the problem terms. If you just exchange them as shown you will pass the challenge.

vincent batteast
vincent batteast
51,094 Points
vincent batteast
vincent batteast
51,094 Points

Thanks i'm sorry. I don't know why I just didn't get that the first time around.

vincent batteast
vincent batteast
51,094 Points
vincent batteast
vincent batteast
51,094 Points

like this

public override bool Equals(object obj) { if (Word.Equals(obj) && VocabularyWord != null ) { return false; } else { return true;
} } } }

this didn't work.

Steven Parker
Steven Parker
231,198 Points
Steven Parker
Steven Parker
231,198 Points

That's essentially the same as the code I commented on, you just renamed the argument. You're still using "VocabularyWord" like a variable, and testing it against null. And still using the Equals method of the string Word to compare it directly to the object.

I added some hints to my answer.

vincent batteast
vincent batteast
51,094 Points
vincent batteast
vincent batteast
51,094 Points

public override bool Equals(object obj) { if(!(obj is Word)) { return false; } else if (obj.Equals(word)) { return true; } }

this is were I'm at now. I think I'm over looking some part. I just not understand why this is not working.

vincent batteast
vincent batteast
51,094 Points
vincent batteast
vincent batteast
51,094 Points

I'm so sorry I'm still not getting it. do you have some article that explain this or some code that I can learn form. I'm just missing something and I don't know what that is.

S.Amir Nahravan
S.Amir Nahravan
4,008 Points
S.Amir Nahravan
S.Amir Nahravan
4,008 Points

public override bool Equals(object obj) { if (!(obj is VocabularyWord)) { return false; } VocabularyWord that = obj as VocabularyWord; return this.Word == that.Word; }

Steven Parker
Steven Parker
231,198 Points
Steven Parker
Steven Parker
231,198 Points

You have a few issues:

  • VocabularyWord is a type but you used it as a variable
  • you use the Equals method of a string to compare it with a VocabularyWord object
  • you may want to compare the new string with the one the object contains instead

Here's a few hints:

  • remember that compiler errors can be seen in the Preview
  • you may first want to test that the argument is a VocabularyWord
  • then you might test for equality with the word inside the argument object
  • you can return the result of your evaluation directly instead of using an If to explicitly return true or false
Steven Parker
Steven Parker
231,198 Points
Steven Parker
Steven Parker
231,198 Points

So, based on your latest code:

  • if (!(obj is Word)) :point_left: "Word" is not a type, but "VocabularyWord" would be
  • if (obj.Equals(word)) :point_left: you don't have "word" anymore, you changed it to "obj", right?

You'll probably want to compare your own "Word" (capital "W") property to the one of the object passed as an argument. To be able to get to it, you might need to apply a cast.

And please use the instructions for code formatting in the Markdown Cheatsheet pop-up below the "Add an Answer" area. :arrow_heading_down:

vincent batteast
vincent batteast
51,094 Points
vincent batteast
vincent batteast
51,094 Points

here were I'm at now. Thank you for the help with this.

'''C# ​ public override bool Equals(object obj) { 

        if(!(obj is Word)) 
        { return false; 
        } 
         var that = obj as VocabularyWord;

        return  (that.Equals(Word));

} '''