Exam 70-483 topic 2 question 131 discussion

Actual exam question from Microsoft's 70-483

Question #: 131
Topic #: 2

You have a class named Customer and a variable named customers.
You need to test whether the customers variable is a generic list of Customer objects.
Which line of code should you use?

A. Option A
B. Option B
C. Option C
D. Option D

Show Suggested Answer

Suggested Answer: D 🗳️
If you want to check if it's an instance of a generic type:
return list.GetType().IsGenericType;
If you want to check if it's a generic List<T>:
return list.GetType().GetGenericTypeDefinition() == typeof(List<>);
Reference: Testing if object is of generic type in C#
http://stackoverflow.com/questions/982487/testing-if-object-is-of-generic-type-in-c-sharp

by Xavios at April 29, 2019, 11:10 p.m.

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Xavios

Highly Voted 6 years, 1 month ago

Should be A

upvoted 30 times

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Mitsoshima

Highly Voted 6 years ago

Got it tested...it's A

upvoted 20 times

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noussa

Most Recent 4 years, 5 months ago

The correct answer is A

upvoted 2 times

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mohmou

4 years, 11 months ago

A: Tested

upvoted 5 times

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whtvr

5 years, 3 months ago

With D the actual type returned by the GetType() would be "System.Type", so no way it would work

upvoted 4 times

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sscooter1010

5 years, 4 months ago

A is correct. Option D will compile, but will not do what is intended. Additionally, the compiler will issue this: warning CS0184: The given expression is never of the provided ('List<Customer>') type

upvoted 5 times

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dakuan

5 years, 7 months ago

A is correct.

upvoted 7 times

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