Introduction to HashMap & HashTable in Java

Рет қаралды 73,134

Күн бұрын

In this video, we'll dive deep into the world of hashmaps, exploring their inner workings, techniques like chaining and open addressing, and even delve into hashmap implementation in Java.
Take part in the learning in public initiative! Share your learnings on LinkedIn and Twitter with #DSAwithKunal & don't forget to tag us!
👉 Resources
- Join Replit: join.replit.com/kunal-kushwaha
- Lecture code: replit.com/@KunalsReplit/Hash...
- Complete Java DSA playlist: • Java + DSA + Interview...
- Code, Assignments, & Notes: github.com/kunal-kushwaha/DSA...
➡️ Connect with me: kunalkushwaha.com
👨‍💻 Join WeMakeDevs: wemakedevs.org
===================================
Timestamps:
00:00:00 Introduction
00:10:25 How Hashmaps work
00:25:46 Chaining
00:49:14 Open addressing
01:06:23 Hashmaps in Java
01:17:09 Implementation
01:38:40 Closing remarks
#placement #hashmap #dsa

Пікірлер: 119

@KunalKushwaha 8 ай бұрын

👉 Resources - Join Replit: join.replit.com/kunal-kushwaha - Lecture code: replit.com/@KunalsReplit/Hashmaps

@roshanchauhan1123 8 ай бұрын

Thanks Kunal bhaiya ,, aap se contact me aana tha kya karu

@aakashsharma8086 8 ай бұрын

A very talented teacher with no haters

@sachinmishra803 8 ай бұрын

😂😂

@LowkeyCoder 7 ай бұрын

💀💀💀💀

@LowkeyCoder 7 ай бұрын

Bhai aache log ke haters to hote hi hai uske liye hi

@notjod4948 8 ай бұрын

When He teaches things gets simpler ! Thanks Kunal Bro!

@thesavageindian5136 8 ай бұрын

Thanks a lot kunal Bhaiyya ❤ Please increase the pace of this course because we are getting paused while learning due to long gaps of new videos

@GouravKumar-ep3hr 4 ай бұрын

Thanks for teaching us for free, explaining the complex concept with simple & easy approach.

@dattajadhav5705 8 ай бұрын

He is the guy who can compromise with setup but not with quality of content and explanation 💫💫💫

@Coding-Just 7 ай бұрын

Kunal is not just a mentor he is person who help us to achieve our goals without any fake suggestions.

@rupashreescanvas2562 8 ай бұрын

Thank you so much Kunal da,for uploading the rest parts gradually.

@techiesworld2112 8 ай бұрын

Had been waiting for this kunal bhai..thank you very much❤

@Isagi__000 8 ай бұрын

Thanks for still doing it. We are lucky to have you

@SanjayPatel01 8 ай бұрын

Thank you sir for uploading the video ❤

@vinayakjaiswal9976 8 ай бұрын

Kunal bhaiya one request while making these DSA videos also mention 3-4 projects in which these data structure has helped you and how😊

@elco7956 8 ай бұрын

I don't think stuff like this is used in development on a daily basis DSA and Leetcode help you learn how to think like a programmer and are needed to clear interview rounds in big tech companies, but you will not really be inverting binary trees all day once you get a job as a SWE

@Hamim-Talukdar 8 ай бұрын

Thanks a lot Kunal vi for giving video again🔥Love from Bangladesh💙

@faizaankhan8090 8 ай бұрын

Thanks a lot Kunal. Your videos helped me a lot!

@LowkeyCoder 8 ай бұрын

Ssly hashmap is here couldnt be any more happier!

@darshanbs2267 3 ай бұрын

You are just amazing kunal really i dindt understood dsa in my college better than here

@upsidedown6204 6 ай бұрын

Thank you bhaiya ! for such an amazing lecture.

@innovativethinker797 7 ай бұрын

Nice lecture lot of new things learnt from this lecture good👍 ahead bro and share your knowledge📚. It's very helpful for students who are curious about learning DSA stuffs

@nareshkamurthi05 8 ай бұрын

Please Complete DSA as soon as possible

@curiosity600 7 ай бұрын

Excellent Sir! Keep teaching Sir🤲

@vaibhavimishra763 8 ай бұрын

Best best best course even paid course can't beat this DSA course ❤❤❤

@user-ml1mg1fd4g 8 ай бұрын

Bro I have been waiting for this video or a longtime ,this video push my motivation to a new level

@sourabhkumar5815 8 ай бұрын

Appreciate your efforts Kunal. 🙌

@abhinavmathur6072 8 ай бұрын

Thanks bro... been waiting for it since long time

@samiranroyy1700 8 ай бұрын

Thanks sir ❤ pls come with dsa series

@abhishekkgupta4294 8 ай бұрын

was waiting for it love your video Kunal

@sachinsingh6244 8 ай бұрын

Waiting for next Video ❤ this was lit🔥🔥🔥as always!

@ABHILASHHAMSA 2 ай бұрын

00:05 Introduction to HashMap & HashTable in Java 02:06 Hashmaps provide a way to search for elements in constant time. 06:43 HashMap in Java is a key-value pair data structure that allows fast retrieval of values based on their keys. 09:12 HashMap and HashTable are used in various areas such as programming languages, network routers, virtual memory, cryptography, and string search. 14:58 Introduction to HashMap & HashTable in Java 17:36 In Java, hash code is a method used to convert a string or number into a unique integer value. 22:34 Hashing is used to reduce large numbers to fit within a predefined range. 24:52 Collision in HashMap and HashTable occurs when multiple indices have the same hash code. 29:39 Assumption of simple uniform hashing for equal likelihood of keys being hashed to any slot in the table. 32:04 The hash function used is k modulo m. 37:41 Understanding the universal hashing method 40:23 The size of the table should be dynamically adjusted based on the number of elements. 45:29 Inserting elements in a HashMap has an average constant time complexity of O(n) 48:51 Open addressing is a method to prevent collisions in HashMap & HashTable. 54:07 Double hashing is used to avoid clustering in hash tables. 56:56 Hashmaps in Java: Understanding the internal workings of hashmaps 1:02:17 Open addressing is efficient in terms of cache performance and memory usage 1:05:06 Open addressing in HashMap degrades past 70% due to clustering and array size reduction. 1:09:39 Introduction to HashMap & HashTable in Java 1:13:30 HashMap vs HashTable in Java 1:18:38 Introduction to HashMap & HashTable in Java 1:21:31 HashMap can be used to remove a key from the map. 1:28:18 Introduction to HashMap & HashTable in Java 1:31:29 Understanding the basic operations of HashMap and HashTable in Java 1:37:28 Introduction to HashMap & HashTable in Java 1:39:30 HashMap and HashTable are important data structures in Java. --------- Definitely his way of teaching lets the topic sink-in in much better way, here are some timestamps.

@BrxkenBxT 8 ай бұрын

Thanks a lot Man! Nobody expected that you'll upload 3-4 videos together.... Hats off to your efforts🫡🫡

@user-fp3ho3qg2b 17 күн бұрын

is this a live video?......people take 100s of cuts in their video to give the content and you are making a lecture live and the content you provide is really so top notch...................really need your type of mentor on this platform....................you are really great kunal bhaiya......................your content is far more better than millions subscriber youtube channel........................i save my 100s of hours by seeing your lectures....................hope you continue this great work of spreading knowledge🙌🙌🙌🙌🙌🙌🙌🙌😊😊😊😊😊😊

@exploring_my_world 8 ай бұрын

Thank you kunal bro❤

@shashankpratapwar-wj7xl 8 ай бұрын

The Messiah of dsa for beginners❤

@pratikbhange2757 8 ай бұрын

Thank you bro🙌

@user-hu7ed8yq2c 5 ай бұрын

Great Lecture Loved it......

@chiraagb 4 ай бұрын

8:45 Applications of hashmaps so that lookup is in O(1) 1) Symbol Table {a table where each variable is pointed to its data type and the value in short} (in compilers {C++, Java} and interpreter {Python, JS}) 2) Network Routers {routing the IP addresses} , Port to IP binding 3) Cryptography 4) String search (grep command)

@xtttra 12 күн бұрын

simple, very easy, very simple stuff

@yahyamohamoud7290 8 ай бұрын

Great video as usual

@sameerakhatoon9508 8 ай бұрын

Tysm!!🙏

@VaibhavSharma-zj4gk 7 ай бұрын

Thank you bro.

@preetichib2254 6 ай бұрын

mind boggling but great stuff

@MangekyouLevi 5 ай бұрын

Great Video!

@arab2aljaafary72 8 ай бұрын

great teacher ..respect from syria🧡

@user-wv8zc7om6m 8 ай бұрын

Thanks you so much bro

@dhruvdangi_ 8 ай бұрын

This video come out at 2 Am in India And I am gonna watch it in 2 am

@hardikraichura9123 16 күн бұрын

mention in ur cv

@ashutoshsingh-uh4io 8 ай бұрын

finally u r back

@karndeeps7547 8 ай бұрын

Superb 🎉

@aryanarora9324 8 ай бұрын

I was just searching for Hashing from Kunal. Dint found the video and now he uploaded it 😂

@vijaybenz9741 8 ай бұрын

Amazing video

@jacksongeorge4047 8 ай бұрын

Good one

@ritikverma4480 23 күн бұрын

@KunalKushwaha I had one doubt that when we are trying to perform put operation and when our size / list.size > lf we are trying to rehash so the current item that we are trying to put will never be added to the original list ?

@rho992 7 ай бұрын

Hi Kunal do you have a video on Dynamic Programming

@sinbad552 6 ай бұрын

21:55 where he trolls the over smart people is just too funny 😂

@sanjaysirangi9788 7 ай бұрын

Waiting for Advanced Tree questions and DP....❤

@preethamroyal5134 8 ай бұрын

Kunal can you please make a video on nested collections please!!!

@poorpanda9033 8 ай бұрын

Let's gooo

@ARYANKUMAR-gz2qw 7 ай бұрын

The real G.O.A.T 🔥

@geetanshkaul3419 8 ай бұрын

FINALLLLLYYYYYYYYYYYY

@LavKushwaha 8 ай бұрын

King Uploaded His DSA VIDEO AT 2 AM 🥷❤️‍🔥 #DSAWithKunal

@user-mo3mi5gr3o 29 күн бұрын

Bro he lives in London so he didn't upload this video at 2 AM

@abhishekkgupta4294 6 ай бұрын

kunal please make one practice leetcode questions video on hasmaps needed

@mjdev3314 8 ай бұрын

❤❤❤

@rohanmallick2963 8 ай бұрын

Finally

@Akhil_NK 8 ай бұрын

BHAIYA on a serious note your videos are seriously means seriously great but bhiaya plz as a freasher its almost impossible to chose which topic to learn first can you plz prepare a road map for this playlist on java + dsa plzzz please note this bhaiya

@KunalKushwaha 8 ай бұрын

just follow the playlist order

@avasthishan 7 ай бұрын

Hello, on the notepad please write on dark paper with a white ink.

@riyabanerjee5599 8 ай бұрын

46:04 I have a doubt when doubling the size of hashmap how is O(1+2+4+8...n) becomes O(n)

@KunalKushwaha 8 ай бұрын

Watch time complexity lecture

@user-lr5qx6lh2i 8 ай бұрын

Constants and less dominatings are ignored

@ajitupadhyay3744 21 күн бұрын

Sum of all powers of 2 up to N can be calculated as 2 log2(N) + 1 - 1. In this remove the constant value

@thechildofprophecy9135 8 ай бұрын

Finnally finnally finnally finnally FINNALLYYYYY 😭

@himanshusahu3969 3 ай бұрын

how do i get this documentation ?

@RahulBisht_001 8 ай бұрын

Please upload DP video

@manashkhatowal7600 6 сағат бұрын

nice

@simalinaaz5640 8 ай бұрын

2am show💯❤️

@andretheruler714 8 ай бұрын

the mere fact that you got 88/100 and you didn't consider that a good grade, shows the level you are at, god tier

@piyushupreti8079 8 ай бұрын

Hey! Kunal I thought the next video you said would be of questions of binary tree

@KunalKushwaha 8 ай бұрын

I have posted that already and advance one will come as well

@piyushupreti8079 8 ай бұрын

With all due respect, When this series will be completed? It’s almost 2 years since the series was started

@raghvendrasingh1981 5 ай бұрын

@@KunalKushwaha plz upload advance binary tree question

@RishiRajxtrim 8 ай бұрын

👍🙏

@Aditi-do4im 8 ай бұрын

First one ❤

@Devnpatel001 8 ай бұрын

Hii, I am studying this DSA course from Canada🇨🇦 and I am in high school right now, I have one question that after completing this Java DSA course do I need to learn anything more to get ready for a job?? I need some guidance, Pls be helpful 😊

@krishanrajoriya 8 ай бұрын

You should do development also...

@Devnpatel001 8 ай бұрын

Thanks a lot for ur helpful reply😊👍

@sahilpandey1757 8 ай бұрын

I want all these videos in Hindi

@kanny8742 8 ай бұрын

Believe it or not, i am following his playlist from 2 years😂

@SajjadAhmed-lc2dr 3 ай бұрын

there was bug coz size of list was increasing so when the value of size changes modulas will be different.

@beachwave5705 4 ай бұрын

gracias wey eres muy pero muy inteligente

@ayushkandwal8851 3 ай бұрын

yaa he is

@vishalvivekm 8 ай бұрын

First

@Akhil_NK 8 ай бұрын

@KunalKushwaha 8 ай бұрын

just follow the playlist order

@uyinokuta3083 4 ай бұрын

This is soooooo complicated and difficult to understand 😭😭😭😭

@namshaanees7215 3 ай бұрын

your voice is similar to kenny sebastian

@RidoyChandraDey 5 ай бұрын

Chaining and Open addressing part was so blurry for me. I am just feeling overwhelmed for it.

@codesetter2497 8 ай бұрын

first

@SarthakCodes 8 ай бұрын

Demn 2 AM drop

@SanjayPatel01 7 ай бұрын

Panauti 28:40 😂😂😂

@abhaysahu-1910 7 ай бұрын

Kunal is obessed by karan marks 😂😂😂

@Kunaltwts 8 ай бұрын

Are you in india ?

@LearnByDoing_932 8 ай бұрын

Ofcourse he is an indian you can watch his Wikipedia

@Kunaltwts 7 ай бұрын

😂 I asked his location

@YashTrivedi-iq3ft 3 ай бұрын

nah his job is in london and makes video from there only @@LearnByDoing_932

@user-mk7qi6gc2m 17 күн бұрын

@@Kunaltwts he lives in london

@abhinavmathur311 7 ай бұрын

22:00 amortized constant time 25:48: collision resolve: chaining--- 30:30 simple uniform hashing 41:23 size of table 47:07 amortized/average constant time explained 50:00 collision resolve-open adressing

@ShantanuSingh-nu7kv 3 ай бұрын

2 $ pepsi, Kunal bro SEXY!!!

@ennen05 Ай бұрын

25:44 12/05/24

@harshitagnihotri4018 8 ай бұрын

🥱

@as_if 6 ай бұрын

4:30 hasmap for O(1) time complexity in searching 8:30 example Not that good of a lecture. Surely, bro has covered probably all the things but the lecture flow is not that of a teacher