Top 10 Java collections framework interview questions for experienced[Most asked interview question]

[@gsaravanan41]

00:32 How does HashMap work in Java? 05:18 What is the difference between fail-fast and fail-safe Iterators? 06:57 The difference between HashMap and Hashtable? 08:10 When do you use ConcurrentHashMap in Java? 09:40 What is CopyOnWrite Array List, how it is different than Array List and Vector? 11:00 While passing a Collection as argument to a function, how can we make sure the function will not be able to modify it? 11:47 How to decide between HashMap and TreeMap? 12:49 What is Comparable and Comparator interface?

[@sachinsingh-hm7cj]

Hii, Thanks for uploading the live interviews they are of great value. If possible can you upload a pdf of mostly encountered questions/topics company wise it will be very helpful to follow up. thanks ☺️

[@JavaTechies]

Sure, I will create one and will share the link in description

[@PetTalks.]

Thank you very much If you prepare the pdf...🙂

[@bantypatel7267]

Great explanation 👍

[@dp-sg8hc]

Hi, Thanks for uploading valuable content. please Java8-Java11 interview questions as well.

[@pranoydas9654]

For a pojo class, why do we need to create or override hashcode and equals method ?

[@JavaTechies]

To change the behaviour according to our requirement, like differentiate on the basis of I'd only

[@navyaj1527]

Sister please provide CV preparation tips too

[@irckdwrld]

Hi, Thanks for helping those who are planning for job change. I have a doubt and a request. Doubt: What's the difference between segment and bucket when we talk about ConcurrentHashMap. Request - If you're taking mocks even now, can you please provide the URL of the form, where we can fill details to schedule a mock interview.

[@JavaTechies]

@Stoic Guy Bucket is the complete array( by default 16 segments in a bucket). Hope I cleared your doubt. Join us on telegram, you will find the link in pinned messages.

[@vickygill07]

Hi, good job. The way you have started the video was good with an example. But later on, it was totally theoretical what everyone can google and find. It would be best if you have explained the topics with some sample example or code. This will help those who won't understand much from theory concepts. Best of luck with future videos.

[@JavaTechies]

Thanks Vikas,yes this was our first video apart from Interviews, we have created a couple of more videos also, these are with code snippets

[@navyaj1527]

Well done sis, thank you soo much

[@rexsam3134]

What are the limitations of storing data in HashMap? What if there is huge amount of data where the linkedlist too may cause issue like what they have discussed in binary tree enhancement in Java 8?

[@JavaTechies]

Thread safety is one limitation. Linkedlist serve a different purpose, we go for map in case we need key value pair, otherwise we go for lists or array only

[@rexsam3134]

@@JavaTechiesMansi : so for a huge data volume only ArrayList is a probable option. Can you have a topic on when to use which collection w.r.t. data volume? Also you mentioned to use CopyOnWriteArraylist being preferred over ArrayList? Did any of your projects used this?

[@prakashbtw678]

Thanks a lot for sharing valuable things. Please tell me steps followed by you to track JP Morgan.how did you apply to JP Morgan and how you got shortlisted..

[@JavaTechies]

I updated Naukri portal almost daily and also filtered out few companies that I liked and put my resume over their career site. These 2 things helped me to get through very good companies like JP Morgan, Morgan Stanley, Oracle, FIS, Ciena.

[@prakashbtw678]

@@JavaTechies thanks a lot for reply

[@JavaTechies]

@@prakashbtw678 definitely it matters, well organised informationand latest 3 projects, make sure you mention your role in each

[@prakashbtw678]

@@JavaTechies thank you

[@JavaTechies]

@@prakashbtw678 welcome 🙏

[@BabaBabaji]

Keep update this type of video

[@JavaTechies]

Thanks 👍

[@subramanianchenniappan4059]

Thanks

[@ramkumar_balu]

Very useful

[@JavaTechies]

Thank you, if you have any specific questions, feel free to ask, I will include them in coming videos

[@ramkumar_balu]

@@JavaTechies Can we have a session on Generics?

[@JavaTechies]

@@ramkumar_balu sure

[@prakashbtw678]

We have many design pattern, Pls list out design pattern to learn and crack product based company interview??

[@JavaTechies]

Sure, Learn all the 5 creational design patterns, template, observer and strategy. Also learn SOLID Principles.

[@JavaTechies]

Creational includes singleton, prototype, factory, abstract factory,builder design patterns

[@prakashbtw678]

@@JavaTechies thank you. Do you suggest any website, udemy course, plural website.. Etc to learn from basic??

[@JavaTechies]

@@prakashbtw678 Telusko from youtube, best and quick

[@prakashbtw678]

@@JavaTechies thank you

[@ashwindhoke4411]

Which is the best book/online portal to learn Core Java?

[@JavaTechies]

If you have time then for core java deep understanding go for java tutorial by durga sir. Telusko also share good lectures and his lectures are quicker as compared to Durga sir. You can choose the best suitable to you. Thanks

[@personelpurpose1531]

Is careergap ok for java can I rejoin after having 1+ year break

[@gajanannandawadekar2075]

Manasi you are great. Please upload L &T pseudo code asked in interview?

[@JavaTechies]

Thankyou, Here is the link for the same javaconceptoftheday.com/find-frequency-of-all-digits-in-number-in-java/

[@mail2zingo]

I think in the video it is mentioned that equals in Object class does reference and content comparison, while equals in String class does content comparison only. This would be incorrect.

[@JavaTechies]

It can be incorrect, thanks for noticing and corrections

[@mail2zingo]

@@JavaTechies : Thanks for replying. I believe equals() in Object class does reference comparison only, while String has overridden equals() by including content comparison as well by checking if the object being considered is of String class. Hence, if we compare two String variables, one initialized as a constant, while the other initialized with a String constructor would fail == comparison, but pass equals comparison.

[@morning8474]

Thanks