Question

I have 2 classes:

public class Item {
   //MyFields
}

public class ItemCapsule {
    public Item MyItem { get; set; };
}

Somewhere in code, I write

ItemCapsule itemCapsule;
if (itemCapsule  != null && itemCapsule.MyItem != null) {
    //action
}

I might want to do this:

ItemCapsule itemCapsule;
if (itemCapsule  != null) {
    //action
}

So I created, in ItemCapsule, 2 methods to overload the operators

public static bool operator ==(ItemCapsule capsule, ???? what to write ????)
{
    return ???? what to write ????;
}

public static bool operator !=(ItemCapsule capsule, ???? what to write ????)
{
    return ???? what to write ????;
}

But, the problem is I do not know how to write the above two methods.

I want to do the following

ItemCapsule != null

which actually is suppose to do the following

ItemCapsule != null && ItemCapsule.MyItem != null

How do I do it?

Answer 1

Usually you do an overload for the equals too.

like so

        public static bool operator ==(ItemCapsule  x, ItemCapsule  y)
        {
            bool xnull, ynull;
            xnull = Object.ReferenceEquals(x, null);
            ynull = Object.ReferenceEquals(y, null);
            if (xnull && ynull) return true;
            if (xnull || ynull) return false;
            return x.Equals(y);
        }

        public static bool operator !=(ItemCapsule  x, ItemCapsule  y)
        {
            bool xnull, ynull;
            xnull = Object.ReferenceEquals(x, null);
            ynull = Object.ReferenceEquals(y, null);
            if (xnull && ynull) return false;
            if (xnull || ynull) return true;
            return !x.Equals(y);
        }

        public override bool Equals(object obj)
        {
            if (obj == null) return false;
            return ((ItemCapsule )obj).Id == Id;
        }