In C#, which keyword is used in method declarations to overload operators for user-defined types?

Introduction / Context:
Operator overloading syntax hinges on one specific keyword in C#: 'operator'. This question confirms that you know the correct keyword to declare overloaded operators.

Given Data / Assumptions:

• You are writing a user-defined type and want to overload an operator such as +, -, ==, etc.

Concept / Approach:
The general pattern is 'public static ReturnType operator +(Type a, Type b)'. Only the 'operator' keyword is valid here; there are no alternative or alias keywords for this purpose.

Step-by-Step Solution:

Verification / Alternative check:
Create a minimal class and attempt to compile with each proposed keyword; only 'operator' compiles.

Why Other Options Are Wrong:
They do not exist in the C# language specification.

Common Pitfalls:
Confusing C# syntax with other languages or inventing pseudo-keywords.

Final Answer:
operator