Generating Equality Members
The implementation of equality methods (i.e.
GetHashCode()) as well as equality operators (i.e.
!=) in the
guarantees reference equality.
In a type you create (which ultimately derives from
Object and thus implements reference equality by default),
you may want to implement value equality for objects of this type
and use the hashcode as a unique object identifier for hashing purposes.
In this case, you need to override equality methods and operators for your type.
In the example below, this command is used to generate
GetHashCode() methods based on
To generate equality members for your type
- In the editor, set the caret within a type, at the line where you want to insert overrides for equality members.
- Press Alt+Insert or choose in the main menu .
- In the Generate pop-up menu, select Equality Members.
If you do not select any fields, ReSharper, depending on your settings, throws new
NotImplementedException(), returns default value, or puts code that will not compile in the body of the generated
GetHashCode()methods. You can configure the settings on the Code Editing | Members Generation options page.
Optionally, use the following controls:
Overload equality operators
generates custom equality and inequality operators (i.e.
!=) for the current type.
Implement IEquatable<T> interface
implements a type-specific
- GetHashCode already exists and Equals already exists appear if the corresponding overrides already exist and let you indicate whether to:
Comparand type check
allows you to choose how the
Equals()method will compare object types:
- Overload equality operators generates custom equality and inequality operators (i.e.
to complete the wizard.
You can also click Options to review or modify commmon code generation preferences on the Code Editing | Members Generation page of ReSharper options
You can also generate the two overrides by choosing Overriding Members in the Generate menu, but in that case they will both return base methods.
As an alternative to generating equality members within your type, you can generate equality comparer class for your type.
This feature is supported in the following languages/technologies:
The instructions and examples given here address the use of the feature in C#. For details specific to other languages, see corresponding topics in the ReSharper by Language section.