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Thanks alot Jeff, I can now safely put Javascript on my resume.

All 100+ Topics: 1. Web Browser 0:43 2. Html 0:55 3. High Level 0:58 4. ECMA 1:07 5. WASM 1:11 6. Runtime 1:16 7. Scripting Language 1:23 8. Browser Dev Tools 1:26 9. Interpreted 1:34 10. V8 Engine 1:42 11. Just In Time Compilation 1:47 12. Script Tag 2:00 13. Src Attribute 2:04 14. Console Log 2:06 15. Let 2:17 16. Dynamically Typed 2:25 17. Primitive 2:30 18. Mutable 2:06 19. Undefined 2:41 20. Null 2:46 21. String 2:50 22. Object 2:54 23. Semicolons 3:00 24. Const 3:13 25. Var 3:21 26. Lexical Environment 3:29 27. Global Scope 3:35 28. Function 3:50 29. Local Scope 3:43 30. Block Scope 3:46 31. Hoisting 3:55 32. Function Definition 4:00 33. Arguments 4:06 34. Return 4:10 35. Function Expression 4:14 36. Higher Order Function 4:19 37. Closures 4:26 38. Call Stack 4:31 39. Heap 4:40 40. this 4:51 41. Window Or Global 5:02 42. Bind 5:11 43. Arrow Function 5:16 44. Anonymous 5:22 45. Passed By Value 5:30 46. Passed By Reference 5:36 47. Object Literal 5:46 48. Object Constructor 5:52 49. Property 5:56 50. Prototype Chain 6:00 51. Inheritance 6:11 52. OOP 6:19 53. Classes 6:22 54. Constructor 6:25 55. Get/Set 6:34 56. Instance Method 6:39 57. Static Method 6:42 58. Array 6:46 59. Set 6:53 60. Map 6:56 61. Garbage Collection 7:05 62. Weakmap & Weakset 7:16 63. Event Loop 7:26 64. Sync 7:32 65. Async 7:36 66. Single Threaded 7:49 67. SetTimeOut 7:56 68. CallBack 8:04 69. CallBack Hell 8:12 70. Promise 8:18 71. Resolve 8:24 72. Reject 8:30 73. Then/Catch 8:33 74. Async 8:40 75. Await 8:46 76. Try/Catch 8:51 77. ES Modules 9:00 78. Default Import/Export 9:07 79. Named Import/Export 9:19 80. NPM 9:27 81. Node Modules 9:32 82. Package.JSON 9:36 83. DOM 9:45 84. Document 9:52 85. QuerySelector 10:00 86. CSS Selector 10:04 87. Element 10:10 88. QuerySelectorAll 10:16 89. Event 10:25 90. Imperative 10:34 91. Declarative 10:42 92. Components 10:48 93. Data Binding 10:58 94. Module Bundling 11:05 95. Network Waterfall 11:19 96. Dynamic Imports 11:28 97. Node.JS 11:35 98. Express 11:40 99. Cross Platform 11:45 100. TypeScript 11:54 101. ESLint07 12:01

Let's admit it, for most of us, Jeff is probably the only person who can make us spend 12 minutes listening to concepts we've known for ages about a language we use 24/7 🙃

This is beautiful. If you are a beginner you can actually use this as a roadmap to learn JavaScript. You can expand on each concept that he talks about, make detailed notes, watch other videos and so on.

11:32 - This is why I watch these sorts of videos. Every once in a while there's something I didn't know about (code splitting) that I desperately need. It's not about learning, it's about exposure.

All 100+ Topics: 01. Web Browser 02. Html 03. High Level 04. ECMA 05. WASM 06. Runtime 07. Scripting Language 08. Browser Dev Tools 09. Interpreted 10. V8 Engine 11. Just In Time Compilation 12. Script Tag 13. Src Attribute 14. Console Log 15. Let 16. Camel Case 17. Primitive 18. Mutable 19. Undefined 20. Null 21. String 22. Object 23. Semicolons 24. Const 25. Var 26. Lexical Environment 27. Global Scope 28. Function 29. Local Scope 30. Block Scope 31. Hoisting 32. Function Definition 33. Arguments 34. Return 35. Function Expression 36. Higher Order Function 37. Closures 38. Call Stack 39. Heap 40. this 41. Window Or Global 42. Bind 43. Arrow Function 44. Anonymous 45. Passed By Value 46. Passed By Reference 47. Object Literal 48. Object Constructor 49. Property 50. Prototype Chain 51. Inheritance 52. OOP 53. Classes 54. Constructor 55. Get/Set 56. Instance Method 57. Static Method 58. Array 59. Set 60. Map 61. Garbage Collection 62. Weakmap & Weakset 63. Event Loop 64. Sync 65. Async 66. Single Threaded 67. SetTimeOut 68. CallBack 69. CallBack Hell 70. Promise 71. Resolve 72. Reject 73. Then/Catch 74. Async 75. Await 76. Try/Catch 77. ES Modules 78. Default Import/Export 79. Named Import/Export 80. NPM 81. Node Modules 82. Package.JSON 83. DOM 84. Document 85. QuerySelector 86. Selector 87. QuerySelectoral 88. Element 89. Event 90. Imperative 91. Declarative 92. Components 93. Data Binding 94. Module Bundling 95. Network Waterfall 96. Dynamic Imports 97. Node.JS 98. Express 99. Metaframework 100. TypeScript 101. ESLint

the cool thing about JS is that literally everyone can just create an html file, add a script tag and start writing some code, you just need the browser (which everybody has installed) and nothing else. This may seem like a normal thing to us but this is actually one of the main reasons why a lot of programmers started with JS, because of how easy it is to start writing code without previous configurations or installations.

Been learning JS for about a month now with no previous dev experience. It's a good feeling to realize that I really have been learning since I understood most of the video. Now to write down the parts I didn't get and learn those too!

Small addition to handling errors of promises (8:51). You can chain `.catch()` after `await promise` instead of using try-catch, e.g. `const xyz = await promise.catch(error => handleError(error)). I frequently use this syntax when I define a variable that's based on a promise. In this way, the assignment stays in the current scope instead of a new (try-catch) block scope. This means you don't have to declare an empty (let) variable and assign the resolved value from within the try-catch scope, which is especially useful if you want the variable to be a constant. Additionally, in this way the error handling is always close to the async call, and when used properly it can prevent excessive nesting too (i.e. the horizontal Christmas tree). Great video as always, thanks!

I know you see this a lot, but I just got a job as a React developer because of your videos. Even if I still know how to do something, I come back to your channel for reassurance. You have no idea how your work impacts so many lives, I'll make sure I buy you a coffee once my first paycheck comes in lol thank you so much Jeff and Fireship!

This generally covers all the concepts you need to know to become competent with JavaScript. Thanks 👍.

I'm SO HAPPY to "know" all of the 101 concepts presented in this video! I got a job in the beginning of this year, and I'm still an intern, but I'm learning each and every single day. JavaScript is so easy, hard, simple and complicated at the same time! I love-hate it! xD

Would love a Python 101 or a C++ 101 also. Great content as always.

The fact that most of the JS concepts are similar to other languages but the quarks of JS are addressed here is really impressive. I've been an experienced Python programmer for years but trying to learn JS has really trip me up with concept of 'this' and proto dunder. Thank you

Honestly thank you for this video because this is things I try to teach since years. I have probably made about 80% of the same plan as your video but yours is way more clearer. Best !

Started getting serious about learning js a week ago, perfect timing!

This is the best thing to go over before an interview😆always struggling to give a standard definition of this after using it 1000 times

Love this fast funny summary/intro. Comprehensive, amusing, precise. Excellent job!

This vid is really helpful for me. I’m still learning JS and sometime i forgot some concept like lexical environment, async function and ‘this’ keyword. Thank you really!

This was actually extremely useful. I've been coding in JS for several years now and it's great to go back and get reminded of the roots. Thank you for the video! 💖

Sounds exhilarating to me, listening to something i already knew as if I never know, thank you so much you are among the best♥️

I had a job interview and thanks to your Video about Angular I got the job, thank you VERY much!

This actually helped me understand some key concepts and tools in JS without boring me to death, instant sub :)

Absolutely love all your videos, love watching them even though I already know what you are talking about. I want to buy all your courses but unfortunately don't have the cash for it :( thanks for making these available on UKposts!

As a kotlin and python programmer this is actually very educational for learning js

"JS. It's a wonderful programming language to learn for beginners. It's also a horrible programming language to learn for beginners." I 100% AGREE

I'm so happy to see that have all the 101 concepts clear, this makes feel a full programmer

Combining it all together in a such a great way and everything... just... true masterpiece!

For anyone starting out or that don't master the core concepts of Js I would highly recommend Kyle's I don't know js book series. You will be a complete different developer when you finish reading it.

This was amazing! Such a good explanation on such a rapid pace!

thanks dude, you summarized everything I learned for 3-4 months in 12 minutes, very impressive

3:29 29. Lexical Environment (global / local / block scope) 4:05 Function Definition / Function Expression / Higher-Order Functions 4:26 Closure 5:19 Arrow Function (anonymous) 5:30 Passed By Value / Passed By Reference 5:45 Object Literal / Object Constructor 6:03 Prototype Chain 6:20 OOP - class, constructor, getter/setter, instance method / static method, array/set/map, garvage collection, weakmap 7:27 Non-Blocking Event-Loop 10:36 Imperative / Declarative 11:24 Network Waterfall 11:31 Dynamic Imports

This is so cool! I started learning JavaScript early this year and I always feel like I barely know anything about it. But there were maybe 5 concepts I didn't know so I guess I'm doing well.

Perfect timing with this video. I was just going through Eloquent Javascript by Marijin Haverbeke. Currently looking at asynchronous programming with Javascript with web apis like setTimeout(). It is quite satisfying once you have success learning concepts like binding of this in javascript.

Thank you for an insightful video as always! This video could not have come at a better time for me. I have been wanting to learn JS to extend my web dev content on my channel! 🔥

It's been a long time that I touched JavaScript. I forgot some of the concepts. I was looking for a crash course which can help me to cope this situation in less time and can cover all of the topics for me. It was a mess at the beginning to find such tutorials. Then suddenly, the name "Fireship" popped up in my mind and I was thinking that who else would make such tutorial other than him. I looked up for "JavaScript in 100 secs by Fireship". After scrolling a bit, I found this video. Now, I have learned the things that I needed. Thanks Jeff for making such life saving contents for us ❤️

Another banger of a video, Fireship. Great concept and superb execution. Just a small correction at 1:06 """Its standard implementation is called Ecmascript""" Ecmascript is not the implementation, its the standard itself. It's just a (huge) document written in legal-ish english that says how should people make compilers\interpreters\virtual machines untimes\Engines for Javascript. "Implementation" is usually the word we use to call the program(s) that we use to run any language, so an implementations of Javascript would be the actual V8 Engine in chromium or NodeJS or any other VM that can run JS, but ES is just a set of rules governing how to make implementations for JS, not an actual implementation.

This was ridiculously fun to watch. Bravo 🙌

This explains a lot of stuff that other resources don’t bother with - I finally feel like I understand js …as much as one can understand js

That's insanely Amazing how he covered everything in just 12 minutes, Thanks alot Jeff!

Your editing skills along with your Programming skills are top-notch. 👍

Thanks bro, you make JS sound more creepier more than ever

javascript beginner to intermediate to advanced in literally 12 minutes! hats off! 🙌

Thank you! This was the perfect video to refresh my memory before I'm starting my internship this semester.

Speaking of ESLint-I'd love a quick video about formatters and linters in JS and their configuration.

best coding channel on UKposts.

Excellent video! Really putting everything together for me. Thank you!

This video resumes a year of javascript learning. Good job 👍

Can you create the same thing for C or maybe C++ ?

it's great that you noted on classes being syntax sugar for prototype inheritance, but it would be also good if you note that `async` is also eventually a syntax sugar for promises

This is a really cool video! The kind of overview I needed of the language, complete and without distractions, thanks!

Note that at 7:18, there is an error in the code, since WeakMaps can't have primitive values as keys. Garbage collection of the keys only makes sense for pass-by-reference stuff (objects), so passing a primitive was made illegal 🚨

''wtfIsThis" : 100% me When trying to learn 'this'

I started directly with TypeScript, and this really, *really* helped me to understand how the sausage is made. Thanks.

I hate my life.

27 seconds ago. Anyways, these are quality videos. Keep going. And keep up the blame on every languages.

That amazing tutorial. This is exactly what i was looking for, fast, to the point not looking at a viewer as a kid learning for the first time.

I am speechless the promise is truly delivered as it was awaited. Well I tried to catch all of this but I think what matters the most is that at a global scope all the concepts were perfectly explained. Thank you for this mesmerizing experience it's the best video I encountered on UKposts this week. Haddag A.

Last time I was this early youtube had a different icon!!!

Don't use var, forget it exists.

Honestly this is an incredible video cheat sheet. He snuck in more than a hundred here like a boss. This might be the best researched and verified channel in coding. Fireship is just like that

Proud member of the Fireship PRO family 💪 Thanks for the new course Jeff!

JAVASCRIPT is the BEST and the worst programming language. I'M A REACT DEV 😜✅

Despite the economic downturn, I'm so happy😊. I have been earning $ 60,200 returns from my $7,000 investment every 13days•❤️

Thanks Jeff! You are the king of summarizing things!

This is acrually helpful when preparing an interview, thank you very much

What a master class in 12 minutes. Amazing Job, no words, hats off 🎉

It was smooth vid for quick revisions of the core concepts. Thansk jeff

This video made me understand so much about javascript, it has gotten rid of bunch of doubts I had, subscribing rn.

Nice video that allows to refresh our JS knowledge!

Thanks a lot dear, before this video i was banging my head on the table, to actually understand those quirky details of JavaScript as i came from a Java background which is rather intuitive and compliant with standard OOP concepts and UML diagrams.

I’m finally getting around to learning js (coming from data analysis), WOW I wished this was the first video I watched. Great job

The time put in and quality of these videos is incredible!

He reads our mind, one of my friends asked me how to learn js, i was opened youtube to sent him a fcc tut, in front me this came as uploaded 5 min ago :)

Thanks a lot Jeff! The JS content of this channel is amazing.

I have been looking for this video for so long, here you explain things that people are learning months!!

Great video! Have learned JavaScript but use only java at work. Good refreshment!

Thank you so much! Your teachings are TOP NOTCH💯🥇

probably the best revision material

im halfway through Meta's Front end dev courses and you help me more in one video. THANK YOU!

Guys watching this 6 Months ago and not understanding a bit comparing to me today watching it and completely understanding every little detail he said makes me feel sooo freakin proud of my self.

Awesome video! I'd love to see more videos like this one. Maybe Python next?

Great breakdown as always. One question I have as someone who understands these concepts and has been using them day to day for some time now. Why is it that the package lock file is rarely discussed in these types of explainers? I feel like a quick explanation of its purpose could be done within a few seconds to clear up a lot of confusion about a file with such a strong warning comment at the top of it.

Super fast... Crystal clear.. Chrisp.. Amazing video ever Thank you Author ❤

Great video! A small correction. At 2:24 "Is a dynamically typed language which means no data type annotations are necessary" is not necessarily true. For example, Elm is a statically typed language but it also does not require type annotations

the video I needed, Thank you so much!

Been learning JS for most of this year and still managed to learn something from this! also, it appears the video on your JS course on your site only has audio in the left ear

I‘m falling in love with JavaScript all over again, thank you! ❤😮

Thanks alot we need more videos like this

Thanks so much. Would be great if you could make a similar one for node.js

7:18 strings can't be keys in weak maps, only objects can (and in the future, also symbols, as there is a proposal for that)

Hey @Fireship, as you mentionned ElectronJS for building desktop app, you should talk about Capacitor which is the same tool but for mobile apps ... You don't always need React Native :)

Dam man you are so dam special with your extraordinory videos ! this was like a quick effective revision of JS in just 13 minutes ! we will need more of those videos mine ! Just keep it UP !!!

daaamn... so much content packed in so little time... thank you, sir!

Two things: 1. it's not like non-object values are passed by value. They are passed by reference as well, but they are immutable, so you simply can't alter them. 2. heap and stack is not really correct. From a memory management point of view, all these objects are allocated on the heap part of the virtual memory. You can't talk about stack and heap for languages like js, python, or many other interpreted languages. Even some compiled languages occasionally blur the line and they are compiler dependent. For example, some Fortran compilers uses the stack for most of its variable declarations, unless the size (aka the dimension()) of the request is very large. In that case, it silently switches to using the heap for that variable, and you won't know the difference because it will manage deallocation for you when you leave the function.

Your intro was both hilarious and accurate haha!

fast , Crisp, clear , concise what not...just Awsome. want this type of video on java, AWS ........😁

I searched for the motivation I need to learn js, and this came up sounds so poetic thank you!

3:50 Hoisting was new to me. - Thank you for another great video teaching us something new!