Returns the hash code for this instance.
Public Overrides Function GetHashCode As Integer
Dim instance As ValueType Dim returnValue As Integer returnValue = instance.GetHashCode()
public override int GetHashCode()
public: virtual int GetHashCode() override
public override function GetHashCode() : int
The GetHashCode method applies to types derived from ValueType. One or more fields of the derived type is used to calculate the return value. If you call the derived type's GetHashCode method, the return value is not likely to be suitable for use as a key in a hash table. Additionally, if the value of one or more of those fields changes, the return value might become unsuitable for use as a key in a hash table. In either case, consider writing your own implementation of the GetHashCode method that more closely represents the concept of a hash code for the type.
For more information, see Object..::.GetHashCode, and System.Collections..::.Hashtable.
The following example demonstrates how the GetHashCode method can be overridden by a derived value type.
Public Structure Complex Private m_Re As Double Private m_Im As Double Public Overloads Function Equals(ob As Object) As Boolean If TypeOf ob Is Complex Then Dim c As Complex = CType(ob, Complex) Return m_Re = c.m_Re And m_Im = c.m_Im Else Return False End If End Function Public Overloads Function GetHashCode() As Integer Return m_Re.GetHashCode() ^ m_Im.GetHashCode() End Function End Structure
public struct Complex { public double m_Re; public double m_Im; public override bool Equals( object ob ){ if( ob is Complex ) { Complex c = (Complex) ob; return m_Re==c.m_Re && m_Im==c.m_Im; } else { return false; } } public override int GetHashCode(){ return m_Re.GetHashCode() ^ m_Im.GetHashCode(); } }
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 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)); } }
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