Cleaner way to do a null check in C#? [duplicate]

Answer 1

In my opinion, the equality operator is not a safer and better way for reference equality.

It's always better to use ReferenceEquals(obj, null). This will always work. On the other hand, the equality operator (==) could be overloaded and might be checking if the values are equal instead of the references, so I will say ReferenceEquals() is a safer and better way.

class MyClass {
   static void Main() {
      object o = null;
      object p = null;
      object q = new Object();

      Console.WriteLine(Object.ReferenceEquals(o, p));
      p = q;
      Console.WriteLine(Object.ReferenceEquals(p, q));
      Console.WriteLine(Object.ReferenceEquals(o, p));
   }
}

Reference: MSDN article Object.ReferenceEquals Method.

But also here are my thoughts for null values

• Generally, returning null values is the best idea if anyone is trying to indicate that there is no data.

• If the object is not null, but empty, it implies that data has been returned, whereas returning null clearly indicates that nothing has been returned.

• Also IMO, if you will return null, it will result in a null exception if you attempt to access members in the object, which can be useful for highlighting buggy code.

In C#, there are two different kinds of equality:

• reference equality and
• value equality.

When a type is immutable, overloading operator == to compare value equality instead of reference equality can be useful.

Overriding operator == in non-immutable types is not recommended.

Refer to the MSDN article Guidelines for Overloading Equals() and Operator == (C# Programming Guide) for more details.