Amazon Interview Question for Software Engineer / Developers


Country: United States
Interview Type: In-Person




Comment hidden because of low score. Click to expand.
0
of 0 vote

An IEnumerator is a thing that can enumerate: it has the MoveNext, Current, and Reset methods (which in .NET code you probably won't call explicitly, though you could).

An IEnumerable is a thing that can be enumerated...which simply means that it has a GetEnumerator method that returns an IEnumerator.

Which do you use? The only reason to use IEnumerator is if you have something that has a nonstandard way of enumerating (that is, of returning its various elements one-by-one), and you need to define how that works. You'd create a new class implementing IEnumerator. But you'd still need to return that IEnumerator in an IEnumerable class.

For a look at what an enumerator (implementing IEnumerator<T>) looks like, see any Enumerator<T> class, such as the ones contained in List<T>, Queue<T>, or Stack<T>. For a look at a class implementing IEnumerable, see any standard collection class.

- sjain February 25, 2013 | Flag Reply


Add a Comment
Name:

Writing Code? Surround your code with {{{ and }}} to preserve whitespace.

Books

is a comprehensive book on getting a job at a top tech company, while focuses on dev interviews and does this for PMs.

Learn More

Videos

CareerCup's interview videos give you a real-life look at technical interviews. In these unscripted videos, watch how other candidates handle tough questions and how the interviewer thinks about their performance.

Learn More

Resume Review

Most engineers make critical mistakes on their resumes -- we can fix your resume with our custom resume review service. And, we use fellow engineers as our resume reviewers, so you can be sure that we "get" what you're saying.

Learn More

Mock Interviews

Our Mock Interviews will be conducted "in character" just like a real interview, and can focus on whatever topics you want. All our interviewers have worked for Microsoft, Google or Amazon, you know you'll get a true-to-life experience.

Learn More