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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
public boolean Equals (
	Object obj
)
public override function Equals (
	obj : Object
) : boolean
Not applicable.

Parameters

obj

Another object to compare to.

Return Value

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

The default implementation of the Equals method uses reflection to compare the corresponding fields of obj and this instance. Override the Equals method for a particular type to improve the performance of the method and more closely represent the concept of equality for the type.

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();
   }
};

public class Complex
{
    public double mRe;
    public double mIm;

    public boolean Equals(Object ob)
    {
        if (ob instanceof Complex) {
            Complex c = (Complex)ob;
            return mRe == c.mRe && mIm == c.mIm;
        }
        else {
            return false;
        }
    } //Equals

    public int GetHashCode()
    {
        return ((System.Double)mRe).GetHashCode() ^ ((System.Double)mIm).
            GetHashCode();
    } //GetHashCode
} //Complex

public class Complex 
{
    public var m_Re : double;
    public var m_Im : double;

    public override function Equals( ob ) : Boolean{
        if( ob.GetType() == Complex ) {
            var c : Complex = Complex(ob);
            return m_Re==c.m_Re && m_Im==c.m_Im;
        }
        else {
            return false;
        }
    }

    public override function GetHashCode() : int{
        return m_Re.GetHashCode() ^ m_Im.GetHashCode();
    }
            
            public static function main() {
                   var x : Complex = new Complex();
                   x.m_Re = 1;
                   x.m_Im = 2;
                   var y : Complex = new Complex();
                   y.m_Re = 2;
                   y.m_Im = 1;
                   
                   Console.Write(x.Equals(y));                       
            }
}

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

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