I've already gone through question
I understand that, it is necessary to implement ==
, !=
and Equals()
.
public class BOX
{
double height, length, breadth;
// this is first one '=='
public static bool operator== (BOX obj1, BOX obj2)
{
return (obj1.length == obj2.length
&& obj1.breadth == obj2.breadth
&& obj1.height == obj2.height);
}
// this is second one '!='
public static bool operator!= (BOX obj1, BOX obj2)
{
return !(obj1.length == obj2.length
&& obj1.breadth == obj2.breadth
&& obj1.height == obj2.height);
}
// this is third one 'Equals'
public override bool Equals(BOX obj)
{
return (length == obj.length
&& breadth == obj.breadth
&& height == obj.height);
}
}
I assume, I've written code properly to override ==
,!=
,Equals
operators. Though, I get compilation errors as follows.
'myNameSpace.BOX.Equals(myNameSpace.BOX)' is marked as an override
but no suitable method found to override.
So, question is - How to override above operators & get rid of this error?
As Selman22 said, you are overriding the default object.Equals
method, which accepts an object obj
and not a safe compile time type.
In order for that to happen, make your type implement IEquatable<Box>
:
public class Box : IEquatable<Box>
{
double height, length, breadth;
public static bool operator ==(Box obj1, Box obj2)
{
if (ReferenceEquals(obj1, obj2))
{
return true;
}
if (ReferenceEquals(obj1, null))
{
return false;
}
if (ReferenceEquals(obj2, null))
{
return false;
}
return obj1.Equals(obj2);
}
public static bool operator !=(Box obj1, Box obj2)
{
return !(obj1 == obj2);
}
public bool Equals(Box other)
{
if (ReferenceEquals(other, null))
{
return false;
}
if (ReferenceEquals(this, other))
{
return true;
}
return height.Equals(other.height)
&& length.Equals(other.length)
&& breadth.Equals(other.breadth);
}
public override bool Equals(object obj)
{
return Equals(obj as Box);
}
public override int GetHashCode()
{
unchecked
{
int hashCode = height.GetHashCode();
hashCode = (hashCode * 397) ^ length.GetHashCode();
hashCode = (hashCode * 397) ^ breadth.GetHashCode();
return hashCode;
}
}
}
Another thing to note is that you are making a floating point comparison using the equality operator and you might experience a loss of precision.