Question

C# I’m trying to compare two different objects (I’m only comparing identical subfields). But I have another place where there’s a check against null. Now I have a problem, it falls through to comparing the two different objects, and that blows up because it’s not expecting null. I tried to put a new method to compare against object, but it doesn’t want to choose that one.

Is it standard practice when overloading operators == or != to check either for null first? Or is there some way to shortcut a comparison to null?

Answer 1

It is standard practice to check for null in equality operators. Take String for example:

public static bool operator ==(string a, string b)
{
    return string.Equals(a, b);
}

public static bool Equals(string a, string b)
{
    return a == b || (a != null && b != null && string.EqualsHelper(a, b));
}