ValueType::Equals Method (Object^)

 

Indicates whether this instance and a specified object are equal.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

public:
virtual bool Equals(
	Object^ obj
) override

Parameters

obj
Type: System::Object^

The object to compare with the current instance.

Return Value

Type: System::Boolean

true if obj and this instance are the same type and represent the same value; otherwise, false.

The ValueType::Equals(Object^) method overrides Object::Equals(Object^) and provides the default implementation of value equality for all value types in the .NET Framework.

If none of the fields of the current instance and obj are reference types, the Equals method performs a byte-by-byte comparison of the two objects in memory. Otherwise, it uses reflection to compare the corresponding fields of obj and this instance.

System_CAPS_tipTip

Particularly if your value type contains fields that are reference types, you should override the Equals(Object^) method. This can improve performance and enable you to more closely represent the meaning of equality for the type.

When you call the Equalsmethod on a Windows Runtime structure, it provides the default behavior for value types that don’t override Equals. This is part of the support that the .NET Framework provides for the Windows Runtime (see .NET Framework Support for Windows Store Apps and Windows Runtime). Windows Runtime structures can’t override Equals, even if they’re written with C# or Visual Basic, because they can’t have methods. (In addition, structures in the Windows Runtime itself don’t inherit ValueType.) However, they appear to have ToString, Equals, and GetHashCode methods when you use them in your C# or Visual Basic code, and the .NET Framework provides the default behavior for these methods.

The following example demonstrates how the Equals method can be overridden by a derived value type.

public ref struct Complex
{
public:
   double m_Re;
   double m_Im;
   virtual bool Equals( Object^ ob ) override
   {
      if ( dynamic_cast<Complex^>(ob) )
      {
         Complex^ c = dynamic_cast<Complex^>(ob);
         return m_Re == c->m_Re && m_Im == c->m_Im;
      }
      else
      {
         return false;
      }
   }

   virtual int GetHashCode() override
   {
      return m_Re.GetHashCode() ^ m_Im.GetHashCode();
   }
};

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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