#417 – Provide a Type-Specific Equals Method for Value Equality

When you are implementing value equality in a type, you typically override the Equals method that is defined in System.Object.  It has the following signature:

        public override bool Equals(object obj)

You should also add a type-specific Equals method.  For completeness, you can indicate that your class implements IEquatable<T>, which includes the type-specific Equals method.

    public class Dog : IEquatable<Dog>

Below is a complete example, showing us the override of System.Object.Equals, as well as the type-specific Equals method.  Note that the generic Equals method calls the type-specific version.

        // System.Object.Equals
        public override bool Equals(object obj)
        {
            return this.Equals(obj as Dog);
        }

        // IEquatable<Dog>.Equals
        public bool Equals(Dog d)
        {
            if (d == null)
                return false;

            return (Name == d.Name) && (Age == d.Age);
        }
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About Sean
Software developer in the Twin Cities area, passionate about .NET technologies. Equally passionate about my own personal projects related to family history and preservation of family stories and photos.

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