Set and HashSet in Java - Full Tutorial

Full tutorial on Sets and HashSets in Java!
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What exactly are Sets and HashSets in Java? How are they different? How do you use them, and how are they different from Lists and ArrayLists?
We'll learn all about Sets and HashSets (and other types of sets like TreeSets and LinkedHashSets) in this video.
Learn or improve your Java by watching it being coded live!
Hi, I'm John! I'm a Lead Java Software Engineer and I've been in the programming industry for more than a decade. I love sharing what I've learned over the years in a way that's understandable for all levels of Java learners.
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[@CodingWithJohn]

Thanks to Mailgun for sponsoring this video! Head to mailgun.com/john to try Mailgun free today. Let me know if you have questions, or ideas for another video!

[@praveenrock3417]

You have to have way more subscribers for the quality of content you're putting out. Crystal clear presentation of concepts..

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I'll have to start making worse videos till I get more subs!

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What are your thoughts on using var for local variables? Example: var myCat = new Cat();

[@wellingtondefassio4435]

Hey John, i am missing new videos!!❤️

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Sorry! I had a minor surgery that I'm recovering from at the moment so I've been delayed. But don't worry, I haven't gone anywhere, so once I'm doing better I'll be back at it.

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Not all heroes wear capes. John is out here helping me crack Google Cloud system

[@xbz24]

The fact u used breaking bad char names made u the goat,thanks for this John

[@niictar]

It’s amazing having access to Java tutorials with the same quality and enthusiasm other YT channels give to the likes of Rust or the latest JavaScript framework. Thank you John!

[@juanjaimeszuluaga]

Hi John! I'm a student of systems engineering. I'm from Colombia and your videos are making me improve in this language. Thank you!

[@trustytrojan]

even though i knew all about java sets, i still watched this video to appreciate how well you teach these concepts. keep it up youre doing good work for the java community 🙏

[@user-tf6no2wr2u]

In my opinion, John is the best programming mentor on KZbin platform! Thank you so much, John!

[@anubratsahoo1351]

What i couldn't understand from 1 hour long lectures,this guy just taught me under 30 mins hatss offf

[@galdamez3]

I had to learn Java for a new job last year and while many of the concepts like Hash Sets have one-to-one parallels in other languages I’ve used, I’ve yet to read up on how to implement them in Java. This tutorial easily saved me a couple of hours of textbook reading. Keep up the great content.

[@socaljusticewarrior558]

Another high-quality video, John. It actually came at the perfect time for me. I was making a whole lot of spaghetti code with ArrayLists and for loops, but then I realized that I need to focus on learning data structures for a while. This very lesson just happened to be applicable to a project I'm working on right now. I'm messing with an API that gives me random cat facts, and I've been getting a lot of duplicates.

[@CodingWithJohn]

Awesome, I'm glad it helped!

[@jordanparsa7713]

Hey John! Your videos are helping me get through the most important internship of my life. THANK YOU. Humble Request: can you make a video covering serialization/deserialization?

[@aidoka2000]

Awesome, concise and clear explanation. Thank you John. I even enjoy watching the topics I already know, because I just love your way of explaining them.

[@royalmech14]

John. Keep them coming. I’m from india. Haven’t seen anyone who speaks organised. Precised as you do. Love your work. Bless you ❤

[@antonmariadas7747]

Love your courses. Needed a reminder about sets and you made it crystal clear 😊

[@ah_dev]

your videos are helping me understand my Java coursework at Uni! Thanks for all you do John!

[@petergazer8321]

Thank you for all of your videos! You break it down in such an easy way to understand. Can you do a video sometime on serialization with examples and when to use it?

[@evilman667]

As a senior dev, i must say, watching your videos is very relaxing. Thank you.

[@jagan107]

Thank you John for make me understanding difference in using Set() and HashSet() i had this doubt for longer time. Time in the video: 3:12 to 4:21

[@isaacwhiz]

Am really really satisfied with the terms you use and the implementation of the concepts in a simple and easy to understand format. Thank you, Thank you, Thank you

[@ayushmaansural4896]

Man respect ++ , The clarity you gave was commendable !

[@mannieg88]

Thank you, John, your explanations are very straightforward and easy to understand. I like the way you explain in the end how we can use data structures in real-world problems.

[@federico42o]

Thanks John, with you I improve my code and my English. Greetings from Argentina

[@CoffeeDev749]

Thank you, John! Also, I loved the Breaking Bad characters being incorporated into the lesson.

[@galdamez3]

Woh, I did not make the connection to the show and the sample names. I was too focused on understanding the concepts. Good eye!

[@mastershonobi110]

Very good vid. It covers all the good stuff in plain English. Thanks John.

[@olenashov5214]

Your explanation of Java makes it easier to understand. Thanks, John!

[@guzinreidelas]

John, thank you so much for the Java lessons. As someone who is not fluent in English, having to read the error-filled KZbin captions and follow the lesson at the same time, I actually understand your explanation better than my own professor's. Sending a warm embrace from Brazil!

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Que legal, Você siga em frente

[@deykumar5433]

Hi John, I love the way you teach. I really appreciate your hard work and effort. It would be very helpful if you make a series on Dynamic Programming. You have that ability to make complex code easier. Thank you so much for your wonderful videos

[@tabsc3489]

Ran into these at work today, so this is a nice coincidence! Thanks for the great tutorial

[@shafaatalizee8182]

Hi Dear Sir ! I'm associat java developer, and I love the way you delivered the topics, especially Hashset and HashMap because I was so confused on these before I watched your tutorials Thanks ❤

[@MzamoHerbza]

Absolutely clear and awesome quality, John. I love the content

[@chazzhorn7688]

I love your way of explaining these concpts! Thanks John!

[@mislam2565]

Simply Perfect and Perfectly Simple to Understand! Thanks a Ton!

[@jetsfan8437]

This was great. Can we get a video explaining interfaces vs classes and APIs?

[@Devivl]

John, you're VERY cool at explaining complicated things in simple words. Thank you so much! Very cool!

[@michaelbistritzki7560]

This is amazing! Now that I thought about it more deeply the idea is genius. I am studying the course on data structures and an introduction to algorithms and now I am thinking that it is possible, as you described at minute 13:15, to reduce the running time of searching for duplicates in a certain list from O(n^2) to O(n) just by using a HashSet. Thank you so much John for opening this thought to me, I will keep thinking about it in the future.Keep making more videos like this, it helps a lot!🤗

[@integralcialbay4633]

Thanks for the great video! I really enjoyed and learned a lot from it. Just wanted to add one little thing about the difference between HashSet and TreeSet: Elements of a TreeSet need to implement either the Comparable interface or they need to come with a Comparator, since the TreeSet sorts them out whereas HashSet just places them based on HashCode. This is a very small difference, but it can be important sometimes.

[@sachinsonawane3767]

Found at right time. Just when I was feeling low and bored but wanted to explore set interface. Good explanation and examples thankyou

[@ObieR]

This is awesome. Your videos have helped me so much. Thanks for all of your work.

[@abhijeetvdsh]

One of the best tutorial | Complete and Clear with examples

[@Timeless_Trader]

Thanks John, it was quite helpful to remember the working principle an difference between these.

[@semilife]

Thanks John, great clear concise videos. Perfect for a newbie and quick refresher.

[@ivaylokostadinov7543]

Hi, John! Could you make a video explaining encapsulation? Your explanations make it so clear.

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Thank you so much for the detailed explanation this is a gem 😍

[@user-un3qd6tv7l]

Your videos are really good and concise, gives me insight enough. Thanks.

[@polimorphic13]

Excellent video as always. Thank you John!

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Amazing pedagogical skills you have sir. Nice work and thank you

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Great content as always, Please make a tutorial about java futures.

[@m_i_g_u_e_l_]

John you are the best java developer i know, thank you so much for share your knowledge.

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John the way you explain is so good that I don't need to study Java Documentation. Keep it it up. Please also make a video on Marker interface and discuss about cloneable and serializable interface

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Love your videos. So clear 🤌✨

[@gab1crazy]

maannn we just started studying hash and how it works and it's amazing. now I just found this video explaining it !!! THX SO MUCH (:

[@summeray1]

Great and simple explanation! Thanks!

[@letampatrickbienwi4610]

Don’t usually comment but great video , I learnt a lot and I can see the connection with data structures better. Thank you John!

[@laforever401]

Wow! What an amazing video! Thank you so much for this!

[@davidwangonjo2041]

You made it look easy. Thank you John

[@faroukmatamir]

Thanks John, Your video is very helpful to me, please keep it up .

[@raisgamesnz325]

Thank you so much for this tutorial!

[@MatthewWeiler1984]

Thanks for the video. I haven't really used Sets in the past. Looks like I have some refactoring to replace instances where I used a List just to keep track of unique entries.

[@Hianfita]

Great content and incredibly well explained! Thank you sir!

[@ArturBerkut]

100 times thank you! I learn English with and Java too So happy to find your channel here

[@satricon]

Awesome information! Thank you so much!

[@gowsikhaadevasenabathy]

Hi John, your videos are extremely helpful for me as I have joined a software firm after a long career break with no prior experience in Java. Can you please do a video on Persistence since there are not many videos on this topic?

[@humairahalimi3741]

Thanks, this video was great, Very easy and clear explanation!

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It's called a wow video❤ thanks for making it easier

[@shaznd301]

An Excellent Video! Thanks.

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I loved it. I want more videos on collection frameworks. Also more on file handling and swing awt. Jdbc everything. I love your videos.

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Great teaching skills, thank you!

[@humzakhan766]

Thank you john. Loved It. God bless you

[@thomas_m3092]

Great video. Thanks John.

[@Bheemagni]

Happy new year John

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I love your all videos. I improve myself with you Genius

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Very helpful video. You are a life saver man

[@KrzysztofChrzan]

Very informative and usefull video. Cheers from Poland.

[@ksgirish1077]

Thanks for your content. A worth watch.

[@aldoumene6201]

Great tutorial as always John! Can you consider doing suffix arrays? I still struggle understanding it 😅

[@kotyo82]

beautiful explanation , i was worrying about this subject when i was listening my instructor several times ,; but after i found this video , Johns explanation ways very clear , understandable ,also polishing other knowledge of Java , if like button was real , i could destroy it , that much i like this .....thanks John

[@drcl7429]

Understanding interfaces is crucial to grasping this. So make sure you watch his video on it.

[@karlcossaboon7072]

Absolute legend over here Thank you

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Thanks a lot! You really helped me.

[@alphab5543]

Great, many thanks John

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Kudos to you John ! keep the good work

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I swear you are the best John 👊🏾

[@crixi__]

perfect explanation, I love it

[@user-ci9om8vi9f]

Such a great videos!!! 🙂

[@michael_scarn_]

Thank you John! Your videos are really helpful :) Could you please make a video about HashCode and equals contract?

[@AnkitYadav-sk4nw]

Sir you are a Legend ! Thank you so much for your wonderful content.❤

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Hi! Im new in your channel, this video was really helpfull, thanks so much.

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Amazing content as always

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You are really one of the best. Thanks a lot

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Thank you so much for this

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Nice & Informative Video Sir .

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thankk you this will help me in my study

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Thank you professor!

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Give a like before watching the video! And in respect to your work watching the mailgun presentation without skipping it!))

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Wowie....!!! Love content like this. Please... More of it.... Maybe I'll love to see using using GUI stuff

[@Namregnal]

Hey John, great video as always. Any chance for a Comparator and Comparable video? Thank you!

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bros' videos are just gold

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My favourite Java Guru❤

[@sumaiyaansari3105]

You are really great Sir!!

[@stonedcodingtom9097]

Nice tut!

[@kvv8197]

Best explanation ever, thanks!

[@CodingWithJohn]

Glad it was helpful!