Exam 70-483 topic 1 question 1 discussion

Actual exam question from Microsoft's 70-483

Question #: 1
Topic #: 1

You are developing an application that includes a class named Order. The application will store a collection of Order objects.
The collection must meet the following requirements:
✑ Use strongly typed members.
✑ Process Order objects in first-in-first-out order.
✑ Store values for each Order object.
✑ Use zero-based indices.
You need to use a collection type that meets the requirements.
Which collection type should you use?

A. Queue<T>
B. SortedList
C. LinkedList<T>
D. HashTable
E. Array<T>

Show Suggested Answer

Suggested Answer: A 🗳️
Queues are useful for storing messages in the order they were received for sequential processing. Objects stored in a Queue<T> are inserted at one end and removed from the other.
References: http://msdn.microsoft.com/en-us/library/7977ey2c.aspx

by apostolin at Aug. 27, 2019, 1:27 p.m.

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Take2

Highly Voted 4 years, 9 months ago

Hi all. Some of you are wondering why Queue is the correct answer when you are specifically asked to access the collection through 'zero-based indices'. I was also confused about this. The answer is that queues in C# have a method called 'ElementAt()' which takes an int, and returns the correlation object, which is why A is the correct answer. :)

upvoted 11 times

Take2

4 years, 9 months ago

Hope this helped!

upvoted 2 times

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Weldryn

4 years, 4 months ago

This is still not correct as ElementAt() is a LINQ extension method usable on any IEnumerable<> collections. Index based access is always O(1) whereas ElementAt() is O(n) for collections that does not supports index based access. Queues are all about FIFO so the they do not allow the access of any element exept the head (and sometimes the tail). The question is ill-formed because of that. If you want a FIFO collection that allows element access with indices, choose an array and manage the FIFO mechanism yourself

upvoted 2 times

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