July 28, 2014
Returns the hash code for this instance.
Assembly: mscorlib (in mscorlib.dll)
The 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 method that more closely represents the concept of a hash code for the type.
For more information, see Object.GetHashCode.
The following example demonstrates how the 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(ByVal 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