Microsoft Certified Solutions Developer (MCSD) Certification Practice Test

Which keyword is used to obtain a type object of an instance?

1. instanceof

2. type

3. typeof

4. GetType

The correct answer is: typeof

The keyword used to obtain a type object of an instance is “typeof.” This operator is crucial in many programming languages, particularly in JavaScript and C#, because it allows developers to determine the type of a variable or object at runtime. When you apply this keyword to a variable, it returns a string representing the type of that variable, which can be particularly beneficial for debugging purposes and type-checking in dynamic programming environments. In a language like JavaScript, the result can include types like "string," "number," "object," etc., allowing developers to understand what kind of data they are dealing with. In C#, although the behavior can slightly differ as it is statically typed, “typeof” can also be used to get the System.Type object of a static type. The other choices include keywords that either do not perform this exact functionality or serve different purposes entirely. For instance, “instanceof” is primarily utilized to check if an object is an instance of a particular class or interface rather than obtaining a type object. “GetType” is a method used in C# that retrieves the type of the current instance but does not do so strictly as a keyword like "typeof." The "type" keyword itself is not standard in languages like C