IEqualityComparer.GetHashCode(Object) Method

public:
 int GetHashCode(System::Object ^ obj);

public int GetHashCode(object obj);

abstract member GetHashCode : obj -> int

Public Function GetHashCode (obj As Object) As Integer

Parameters

Returns

A hash code for the specified object.

Exceptions

Examples

The following code example demonstrates the implementation of a case-insensitive IEqualityComparer. In this example, the GetHashCode method returns the hash code provided by the Object type.

class myCultureComparer : IEqualityComparer
{
 public CaseInsensitiveComparer myComparer;

 public myCultureComparer()
 {
 myComparer = CaseInsensitiveComparer.DefaultInvariant;
 }

 public myCultureComparer(CultureInfo myCulture)
 {
 myComparer = new CaseInsensitiveComparer(myCulture);
 }

 public new bool Equals(object x, object y)
 {
 return myComparer.Compare(x, y) == 0;
 }

 public int GetHashCode(object obj)
 {
 return obj.ToString().ToLower().GetHashCode();
 }
}

Public Class myCultureComparer
 Implements IEqualityComparer

 Dim myComparer As CaseInsensitiveComparer

 Public Sub New()
 myComparer = CaseInsensitiveComparer.DefaultInvariant
 End Sub

 Public Sub New(ByVal myCulture As CultureInfo)
 myComparer = New CaseInsensitiveComparer(myCulture)
 End Sub

 Public Function Equals1(ByVal x As Object, ByVal y As Object) _
 As Boolean Implements IEqualityComparer.Equals

 Return myComparer.Compare(x, y) = 0
 End Function

 Public Function GetHashCode1(ByVal obj As Object) _
 As Integer Implements IEqualityComparer.GetHashCode
 Return obj.ToString().ToLower().GetHashCode()
 End Function
End Class

Remarks

Implement this method to provide customized hash codes for objects, corresponding to the customized equality comparison provided by the Equals method.

Notes to Implementers

Implementations are required to ensure that if the Equals(Object, Object) method returns true for two objects x and y, then the value returned by the GetHashCode(Object) method for x must equal the value returned for y.

See also

• GetHashCode()
• IHashCodeProvider