Java collections framework interview questions and Answers | MOST ASKED | Core Java

Java collections framework interview questions and Answers | MOST ASKED | Core Java | Code Decode

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Күн бұрын

This video contains tricky Java Collections Interview Questions and Answers for Freshers as well as for Experience Candidates. It also contains Internal Working of Hashmap
Collections Interview Questions part -2 : • Most Asked Java Collec...
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Course Description Video :
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Collection Hierarchy 00:16
Map doesn’t extend the Collection Interface 13:13
Difference between fail-fast and fail-safe Iterators 14:51
java BlockingQueue 16:43
Difference between Synchronized Collection and Concurrent Collection with pictorial understanding 18: 10
Internal Working of hash map with pictorial explanation 20:13
In this video of java collections interview questions we have covered java collection framework interview questions or top collections interview questions starting with hierarchy of collection framework in java
collection hierarchy in java will demonstrate in depth knowledge of candidate.
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In java collections interview questions. java.util.Collection is the root
of the Java Collection framework and most of the collections in Java are inherited from this interface except Map Interface
java.util.List :
Contains ordered elements
May include duplicates
Supports the index-based search, random access but elements can be easily inserted irrespective of the position.
java.util.Queue
follows a FIFO approach
Elements adds at rear end and removes from the front end.
java.util.Set:
Doesn’t define an order for the elements hence index-based search is not supported
Doesn’t contain duplicates
java.util.Map
Represents a key, value pair
Map interface does not implement the Collection.
It can only contain a unique key
can have duplicate values
In java collections interview questions Similarly all these interfaces have implementing class and all those implementing classes have some 2 3 unique feature which differentiate them from the other collections. Please have a look at each of them in video as i have limited word limit here :)
The Java BlockingQueue interface, java.util.concurrent.BlockingQueue, represents a queue which is thread safe to put elements into, and take elements out of from. In other words, multiple threads can be inserting and taking elements concurrently from a Java BlockingQueue, without any concurrency issues arising.
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Пікірлер: 427

@shubhamtagalpallewar7125 3 жыл бұрын

It helped me in my interview preparation.. thanks

@CodeDecode 3 жыл бұрын

Hope you get all your interviews cleared. All the the best 🤟

@suratdas3866 3 жыл бұрын

@@CodeDecode aa

@realnileshpawar 2 жыл бұрын

Kuthe rahto bhau tu? Do u want to take live instructor led classes? I have over 5 years of experience in corporate.

@TheBoysZone 2 жыл бұрын

as ka😂😂😂😂

@accforgame8563 Жыл бұрын

@@realnileshpawar how do i contact u?.

@kirushnashirre6791 3 жыл бұрын

Though I knew about the framework completely, I had an issue explaining it in an organized way, you are just awesome!

@CodeDecode 3 жыл бұрын

Thanks 👍

@rohanbhargava3953 3 жыл бұрын

Great video! One addition to the last question on implementation of HashMap Since Java 8, once a threshold limit is reached for the number of linked list elements added at a particular node, the linked list is re-ordered to a binary tree to implement faster search for collision cases.

@CodeDecode 3 жыл бұрын

Thanks for the info

@JenilCalcuttawala Жыл бұрын

Binary but Binary Search Tree right?

@JustOssetian Жыл бұрын

@@JenilCalcuttawala red black tree

@coincidentIndia 2 жыл бұрын

SortedSet uses Comparator(Comparator

@jasper5016 2 жыл бұрын

It enhanced my knowledge for sure. Thanks.

@mitra.1 5 ай бұрын

Thanks a lot.. The best Collection summary available on YT.

@SuperMilanjain 3 жыл бұрын

Really a nice approach to make understand the topic. Just one request, plz add some behavioral questions related to collection as interviewer can ask that also.

@kathiravanjagadeesan 3 жыл бұрын

Beautiful Effort.IT Field will remember your name forever.

@CodeDecode 3 жыл бұрын

Thanks for wonderful comment kathiravan. you might not know this but you made our day and all the efforts we did now turned meaningful bcz of such nice words🙏🙏. We , team code decode is grateful 🙏🙏. keep learning Kathiravan, you will surely land at your dream place really soon. all the best 👍👍👍👍

@prakashkaruppusamy3817 3 жыл бұрын

This is a awesome 'Ready Reckoner'. I watched this and all are explained clear and to the point. This is great effort by the creator. Please make more topics and please make more videos. I totally understood the points. All the very best team 👍👏 With Regards, Prakash Karuppusamy

@CodeDecode 3 жыл бұрын

Thanks for the nice words Prakash. We will sure make more videos like this ....

@Athira_Surendran 3 жыл бұрын

The way you explaining each topic is awesome. Thank you for the amazing video.

@CodeDecode 3 жыл бұрын

Thanks for the nice words.....

@SamPaulIsaac Күн бұрын

Insightful! Thanks team.

@savitarohra3905 2 жыл бұрын

Everything explained to the point!! Thank you for making great videos

@CodeDecode 2 жыл бұрын

Thanks Savita 👍

@robinbhargava111 11 ай бұрын

Very informative and quick to brush up collection framework with examples.

@CodeDecode 11 ай бұрын

Thanks Robin 🙂👍

@shivaniagrawal4473 3 жыл бұрын

Thank u so much,your way of explaining concepts are wonderful.I am feeling so confident in Java after watching your interview questions.

@CodeDecode 3 жыл бұрын

Thanks Shivani 👍👍. Keep learning keep shining ⭐✨⭐✨

@nikhleshagrawal 3 жыл бұрын

from Java 8, the linked lists are dynamically replaced with balanced binary search trees in collision resolution after the number of collisions in a given bucket location exceed a certain threshold. This change offers a performance boost, since, in the case of a collision, storage and retrieval happen in O(log n).

@CodeDecode 3 жыл бұрын

Yes we have covered that in latest videos I. E. top interview questions 👍👍. Thanks

@jakubdudek4133 Жыл бұрын

For others who are interested in that particular topic, the threshold by default is 8 as far as I remember. :) So "after" 8 nodes, LinkedList is being switched to Tree Balance Structure.

@robelhailab394 2 жыл бұрын

You are awesome, thanks for thanking your time to help us on interview preparations!

@CodeDecode 2 жыл бұрын

Thanks for motivating us to put more efforts for community 🙂. We are glad to do that 🙂👍

@sharathrajesh9494 2 ай бұрын

Hi Mam, this video about collections helped me during my interview with TCS and I secured a job offer! Thank you very much and I will continue to look through your other videos to help broaden my knowledge

@nagavenkatakishore4109 3 жыл бұрын

Nice explanation friend thank you very much for sharing.

@CodeDecode 3 жыл бұрын

Thanks for the nice words 👍

@dasarajusaikumar8585 2 жыл бұрын

your phone vibrates in almost all of your videos. thats very nice :-). it's not a complaint, take it as a compliment

@CodeDecode 2 жыл бұрын

we fixed this issue in new videos. Thanks 👍👍😊😊

@pallavipatare2004 2 жыл бұрын

This is my first ever KZfaq comment. I just logged in to youtube so that I can comment on your video. You are awesome. Very well explained, very well organised. Keep it up. No nonsense videos. I am preparing for my interviews using your videos only. Pls countinue uploading many such videos.

@CodeDecode 2 жыл бұрын

Thanks Pallavi 🙂👍

@GaneshSingh1 3 жыл бұрын

I have read theory before but confused after this video cleared all doubts about Hashmap,, thanks a lot

@CodeDecode 3 жыл бұрын

We are glad to know that this helps Ganesh 🙏👍

@praveenpatel3957 3 ай бұрын

This special video covered all related to collection and its interview questions have watched so many videos about that but here have learnt in very different way thanks for sharing such valuable content in the video keep sharing like this we get to learn more..❤❤

@farrukhahmedsid Ай бұрын

Yes this is literally most asked and top questions. Thanks.

@CodeDecode Ай бұрын

Thanks

@RickyYadav_at_googleplus 3 жыл бұрын

very nicely explained... eagerly waiting for Multi-threading concepts.. once again good job!

@CodeDecode 3 жыл бұрын

Thanks .......

@vinodkumar-lq7oo 3 жыл бұрын

Really very good explanation. We are lucky to watch this.

@CodeDecode 3 жыл бұрын

Thanks Vinod 👍

@sureshgarine 3 жыл бұрын

Thank you so much, madam. You explained in-depth and very nicely

@CodeDecode 3 жыл бұрын

Thanks 👍👍

@kajalkukreja694 3 жыл бұрын

Very good questions and their detailed explanation. Thanks 👍👍

@CodeDecode 3 жыл бұрын

Thanks for the nice words...

@parulanand7902 3 жыл бұрын

Thank you for the amazing video.. It helped me a lot for my interview.

@CodeDecode 3 жыл бұрын

Thanks for writing back to us Parul . We hope u land at your dream job soon. All the very best from team code decode, for your interviews. Keep learning keep growing.

@BhushanRawoolShridhar 3 жыл бұрын

Nice explanation,you are doing a great job. Thank You

@CodeDecode 3 жыл бұрын

Thanks Bhushan 👍👍

@sneharaghuwanshi4933 2 ай бұрын

Hello Ma'am, I have learnt a lot from your channel thank you so much. I have one doubt here that the linked list does not support index based search but it has a get method through which the element is at a specific position?

@venkatv3690 2 жыл бұрын

Best i have seen before the way ur explaining very well thank you

@CodeDecode 2 жыл бұрын

you're welcome venkat

@bhavyabhardwaj4563 2 ай бұрын

Very good explanation of Internal working of hashmap. Liked it.

@CodeDecode 2 ай бұрын

Thanks

@JourneyswithAK 2 жыл бұрын

Seriously very great explanation ❤️

@CodeDecode 2 жыл бұрын

Thanks a lot 🙂🙂👍👍

@robelhailab394 10 ай бұрын

Great Explanation!!! One more point: Hashtable doesn’t extend Hashmap. It extends Dictionary Class.

@CodeDecode 10 ай бұрын

👍👍

@nidhi10sharma 2 жыл бұрын

Excellent videos, Thank you so much!

@CodeDecode 2 жыл бұрын

Thanks Nidhi 🙂👍

@kemparaj565 2 жыл бұрын

Very good. Explanation. Thank You 😊

@CodeDecode 2 жыл бұрын

Thanks 🙏

@satishdhaigude629 Жыл бұрын

Thank you, nice explanation of all collections, mostly I like internal working of hash map, got the more clarity….

@CodeDecode Жыл бұрын

kzfaq.info/get/bejne/bdFgibx52ruqZps.html

@solomonrajkumar5537 3 жыл бұрын

Hats off very nicely explained and your presentation is also too good.

@CodeDecode 3 жыл бұрын

Thanks 👍

@gurudassulebhavikar 8 ай бұрын

In case of hash collision it also uses equals method to check if key is same. If it is same then it updates the value. Otherwise, new node is inserted.

@Hare_Krishna143 2 жыл бұрын

Such helpful content and appreciate your hardwork Thank you mam!!

@CodeDecode 2 жыл бұрын

Thanks Manoj 🙂👍

@anshumanpanigrahi7817 2 жыл бұрын

Ma'am, thank you for this. It really helped me in cracking Amdocs. I was able to recall the exact same thing you taught in this video. I can say, that I've done DSA and used every framework that's why it looked very understandable at the very first go.

@CodeDecode 2 жыл бұрын

Congratulations Anshuman 🎊🎊🎉🎉

@shouryapradhan184 2 жыл бұрын

HI Anshuman , Bro i have an Amdocs interview in upcomming week. Can u pls help me in that like how is the interview and what questions were asked in that interview please ? Can we connect?

@anshumanpanigrahi7817 2 жыл бұрын

@@shouryapradhan184 Topics- Java, Oops, Threads, Collections, SQL, DBMS, Unix commands, 2 programming questions. Go through interview experiences from gfg & Coding Ninjas/CodeStudio, that'll be enough. Mine was for developer profile.

@shouryapradhan184 2 жыл бұрын

@@anshumanpanigrahi7817 Thanks a lot for reply bro. Mine interview is also for developer role 2 years of experience. May i know what type of programming questions were asked in interview ?

@PKS-ky9se 2 жыл бұрын

Thanks for the great video. Helped me a lot.

@CodeDecode 2 жыл бұрын

You're welcome

@Sakshi-gs5tl 12 күн бұрын

Awesome video for java collections 💯💯💯

@CodeDecode 7 күн бұрын

Thanks sakshi 👍

@kaushikigoel759 2 жыл бұрын

Each and every video is so informative!! Love your content ❤️..

@CodeDecode 2 жыл бұрын

thanks kaushiki

@prasannaakolka 3 жыл бұрын

Thanks a lot for the awesome content!!

@CodeDecode 3 жыл бұрын

👍

@anuradhap4055 2 жыл бұрын

Hi.. Your videos are the best. You explain so well. Thanks a ton for your efforts. One request.. can you please make a video on how time complexity works in collection?. It would be a great help. Thanks in advance. 🙂

@Sanketpatil96k 17 күн бұрын

The time complexity of a collection is the amount of time it takes to perform an operation on the collection

@sagarmane3291 2 жыл бұрын

Superbbb...! your explanation skills are just awesome.... and ur voice is adorable as well. thanks for this questions set it will be really helpful

@CodeDecode 2 жыл бұрын

Thanks Sagar 🙂🙂

@danilozimermann7809 2 жыл бұрын

Very well explained! thank you

@CodeDecode 2 жыл бұрын

Thanks 👍👍

@vinayvjs628 3 жыл бұрын

Best study video for interview

@CodeDecode 3 жыл бұрын

Thanks 👍👍

@chishamalama Жыл бұрын

Thank you once again for explaiing clearly

@CodeDecode Жыл бұрын

Thanks Chisha Malama 🙂🙂👍👍

@deviprasadhota2617 Жыл бұрын

Nice work...one mistake is map interface doesnt extends(not implement) Collection interface

@sonalirajashri 5 ай бұрын

its very nice ad helpful.

@CodeDecode 5 ай бұрын

Thanks Sonali 👍

@shubhammowade.6019 3 жыл бұрын

Respect for your explanation ma'am...

@CodeDecode 3 жыл бұрын

Thanks 👍

@kamallochannayak2706 2 жыл бұрын

Thank you mam .....your way of talking/understanding.....love it

@CodeDecode 2 жыл бұрын

You're welcome kamal.....

@kamallochannayak2706 2 жыл бұрын

❤

@shamilraj322 2 жыл бұрын

Thank you for a very detailed explanation. :) Expecting more videos like this.

@CodeDecode 2 жыл бұрын

Sure Shamil. We will upload more videos on collection framework

@sanjeetkrsinha Жыл бұрын

Your video helps me a lot for preparation of interview. Do you have any the text tutorial also for it?

@croydon21H 2 жыл бұрын

Good videos. Question - how can a programmer know, if there was a hashmap collision or not?

@sekhar14301 Жыл бұрын

Thanks for wonderful explanation 🤝

@CodeDecode Жыл бұрын

You are welcome

@neerajkbc 2 жыл бұрын

Thanks for the video, really helpful 👍

@CodeDecode 2 жыл бұрын

You are welcome neeraj...

@avinashrawat5823 7 ай бұрын

very informative Thanks

@CodeDecode 7 ай бұрын

Glad you found it helpful😊

@narendulatharun9624 3 жыл бұрын

Wow great mam thanks for this amazing video🔥

@CodeDecode 3 жыл бұрын

👍👍

@sivasankarbestha 3 жыл бұрын

Very clear explanation.. and provide example code 👍👍👍👍

@CodeDecode 3 жыл бұрын

Thanks Siva 👍👍

@Daxbedivlogs 3 жыл бұрын

just subscribed your channel after this video.. thanks :)

@CodeDecode 3 жыл бұрын

M glad you find this helpful

@shubhamshende9995 2 жыл бұрын

very clear and crisp explaination 💥

@CodeDecode 2 жыл бұрын

Thanks Shubham 🙂👍

@dipabhow4630 2 жыл бұрын

so nice love it

@CodeDecode 2 жыл бұрын

Thanks 🙂👍

@ravikirantakale6616 3 жыл бұрын

Thank you so much for such useful content 🔥🔥🙏

@CodeDecode 3 жыл бұрын

You are welcome.......

@srikarwarrior123 3 жыл бұрын

Thank you so much for the video :)

@CodeDecode 3 жыл бұрын

Thanks for writing back Srikar 👍👍

@rishiraj2548 Жыл бұрын

5 lakh 48 thousand + views Congrats 🎉🎉🎉

@CodeDecode Жыл бұрын

Thanks Rishi for your constant support

@vipinyadav7921 3 жыл бұрын

Very nicely explained, Please make a video on whole springboot concepts... With theory and coding as well

@CodeDecode 3 жыл бұрын

Sure will make a video on that too

@kp-ps7wi 3 жыл бұрын

Explanation is awesome. Just a suggestion. In the diagram just put dotted line for interface and solid line for class. So while seeing the diagram people will understand the concept.

@CodeDecode 3 жыл бұрын

That's a very nice suggestion. Thanks 🙏👍👍👍👍

@TheFebruary10 2 жыл бұрын

Very good to remember and recollect

@CodeDecode 2 жыл бұрын

Thanks Sanjeev 🙂👍

@seethegodinyou 2 жыл бұрын

Thank you so much , I found all my interviews questions from there...We need people like you!

@CodeDecode 2 жыл бұрын

Thanks for nice words chandan

@Rimanshu001 2 жыл бұрын

Good one mam,please continue such videos.

@CodeDecode 2 жыл бұрын

sure we will upload more

@koteshwarvenigalla7150 3 жыл бұрын

Great explanation!

@CodeDecode 3 жыл бұрын

Thanks..

@krishteja2959 3 жыл бұрын

superb.....Nice presentation .If possible, can you please do video like most asked interview questions which covers all the concepts in core and advanced

@CodeDecode 3 жыл бұрын

Sure I will cover all of them, from simple to advanced in parts soon

@PallabChatterjee18 9 ай бұрын

That Map interface point it will be map interface does not extends the collection right ?

@arunkumarmn7493 3 жыл бұрын

Wow great explaination

@CodeDecode 3 жыл бұрын

Thanks 👍

@gokulaher2476 3 жыл бұрын

why java inventors not provided a new overloaded version of add(k,v) which can take two parameters key -value so that MAP interface can also extends Collection interface why there is separate put(k,v) I think the problem would have been solved just by adding one overloaded method add(k,v) pl correct me if I am incorrect

@rajatram5068 3 жыл бұрын

Awesome Explanation

@CodeDecode 3 жыл бұрын

Thanks......

@AK-tt7fc Жыл бұрын

the video is very usefull . at 3.40 you interchangeably used implements and extends keyword . if possible correct that .

@sreejak6776 2 жыл бұрын

Pleasr create more tricky questions on collections

@CodeDecode 2 жыл бұрын

sure sreeja we will create soon

@shivaraja3488 6 ай бұрын

Thank you very much

@CodeDecode 6 ай бұрын

😊👍

@venkatkancharla984 3 жыл бұрын

thanks for all the tricky quaetions, please explain the HashMap with some examples and this is very short. because i was understanding this only theoretically but havent't implemented. bit more explanation on hash map.. it also talks about the equals() and hashCode() contract..

@CodeDecode 3 жыл бұрын

Hi Venkat These are only interview questions. Will create tutorial for this very soon 👍👍

@venkatkancharla984 3 жыл бұрын

@@CodeDecode sure, thanks

@jeevansaimanikanta782 3 жыл бұрын

Thanks . Please do the video showing the internal implementation of HashSet as well and also tell the info like in which scenario which kind of Collection is the suitable one to use

@CodeDecode 3 жыл бұрын

Nice topic thanks 👍

@ammarzafar1337 2 жыл бұрын

Very Well Explained.

@CodeDecode 2 жыл бұрын

Thanks Ammar 🙂👍

@sourabhjinde8191 2 жыл бұрын

Thanks.. that was awesome 👍

@CodeDecode 2 жыл бұрын

Thanks Sourabh 🙂👍

@dineshsolanki1666 3 жыл бұрын

an image with all the information would be great

@praveenagrawal9616 Жыл бұрын

Thanks for the video. It's really helpful for interview preparation. One small doubt I have in 6:57 you said hashset internally implements hashtable and one null value can contain. But hashtable doesn't contain any null key and null value.. Please explain and correct me.

@satishr2071 4 жыл бұрын

Nice video keep it up 👍

@CodeDecode 4 жыл бұрын

Thanks ☺️

@sunitapawar1819 3 жыл бұрын

Nice content.. Thanks

@CodeDecode 3 жыл бұрын

Welcome 👍

@ravikaramunge8028 3 жыл бұрын

Thanks its really helpful 😊

@CodeDecode 3 жыл бұрын

We are glad it's helpful. Thanks for writing back Ravi 👍

@harshadakankhar4875 3 жыл бұрын

Please make a video for Spring interview questions as well..

@CodeDecode 3 жыл бұрын

Sure will do that soon

@harshadakankhar4875 3 жыл бұрын

Code Decode anyway the way you explain is just wow 🤗🤗

@CodeDecode 3 жыл бұрын

thanks :) 👍

@RaghuVN 3 жыл бұрын

I don't get it. There is get method in Linkedlist class. I have heard the same thing in multiple videos. Is it added recently.

@ankush_in_sync5998 2 жыл бұрын

Thank you. Keep it up.

@CodeDecode 2 жыл бұрын

You're welcome ankush

@amitarcade 2 жыл бұрын

For hashmap internal working, hashcode method is called by hash method of HashMap and hash method calculates index based on hashcode value

@CodeDecode 2 жыл бұрын

kzfaq.info/get/bejne/bdFgibx52ruqZps.html

@RaviK-lv9zf Жыл бұрын

Beautiful voice.. 😅 and the content is so good that you almost covered main topics that can consume most of the time at institutes.

@CodeDecode Жыл бұрын

Thanks Ravi 🙂🙂

@nitupandey7520 3 жыл бұрын

Thnks for this video 🙏🏼

@CodeDecode 3 жыл бұрын

You're Welcome...

@sushmakolli1119 3 жыл бұрын

Please make another video(part2)on collections tricky questions and include concepts like internal working of hash set

@CodeDecode 3 жыл бұрын

kzfaq.info/sun/PLyHJZXNdCXsfqAkteaQ6JfZ_IHvxX-Hj3

@brajray2881 Жыл бұрын

Thanks 🎉

@CodeDecode Жыл бұрын

🙂👍

@balakrishnagajam 3 жыл бұрын

Nice one.. Thanks

@CodeDecode 3 жыл бұрын

👍