Compiler Warning (level 3) CS0659

'class' overrides Object.Equals(object o) but does not override Object.GetHashCode()

The compiler detected an override of the Object.Equals method but no override of the Object.GetHashCode method. An override of Equals implies that you also want to override GetHashCode.

The following code generates CS0659:

// CS0659.cs  
// compile with: /W:3 /target:library  
class Test
{  
   public override bool Equals(object o) { return true; }   // CS0659  
}  
  
// OK  
class Test2  
{  
   public override bool Equals(object o) { return true; }  
   public override int GetHashCode() { return 0; }  
}  

See also

• Object.Equals
• Object.GetHashCode
• Equality Operators
• Implementing the Equals Method