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You Don't Know JS #1
You Don't Know JS: Up & Going
It’s easy to learn parts of JavaScript, but much harder to learn it completely—or even sufficiently—whether you’re new to the language or have used it for years. With the "You Don’t Know JS" book series, you’ll get a more complete understanding of JavaScript, including trickier parts of the language that many experienced JavaScript programmers simply avoid.
The series� first book, Up & Going, provides the necessary background for those of you with limited programming experience. By learning the basic building blocks of programming, as well as JavaScript’s core mechanisms, you’ll be prepared to dive into the other, more in-depth books in the series—and be well on your way toward true JavaScript.
With this book you will:
Learn the essential programming building blocks, including operators, types, variables, conditionals, loops, and functions Become familiar with JavaScript's core mechanisms such as values, function closures, this, and prototypes Get an overview of other books in the series—and learn why it’s important to understand all parts of JavaScript72 pages, ebook
First published March 20, 2015
781 people are currently reading
2,445 people want to read
About the author
Kyle Simpson
36books355followersKyle Simpson is an Open Web Evangelist from Austin, TX, who's passionate about all things JavaScript. He's an author, workshop trainer, tech speaker, and OSS contributor/leader.
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Displaying 1 - 30 of 174 reviews
July 2, 2021
Software is eating the world, the web is eating software, and JavaScript rules the web. The irony is that JavaScript (as of 2018) is still a vastly misunderstood programming language regarded in many quarters as a toy or kludge limited to handling DOM manipulations and browser events. Worse, if you're a current front or backend web developer coming to grips with JavaScript you are likely to be misled by hundreds of out-of-date online tutorials purporting to teach you "The Good Parts" of the language to the detriment of an in-depth understanding of the ecosystem, performant code, mechanics of lambdas, closures, prototypes, and other higher order functions.
This is where the You Don't Know JS series by Kyle Simpson rides in, Zorro-like, to save the day. As a first book on JavaScript, it is everything that I thought it could be: concise, tightly written, absolutely disciplined, and devoid of the dead-tree filler found in much thicker programming books. I cannot recommend this series highly enough for anyone interested in JS. Instead of learning just enough to be dangerous, if you work through this series (preferably open in your browser of choice while writing and running all the code examples in your Developer Tools console), you should emerge with an understanding of closures, coercion, scope, hoisting, and the this identifier.
Up & Going also provides a lot of background instruction for those with limited programming experience in any language. As such, it's a great place to start for those new to software development as well as experienced programmers who want to quickly get up to speed on this crucial piece of the web platform.
This is where the You Don't Know JS series by Kyle Simpson rides in, Zorro-like, to save the day. As a first book on JavaScript, it is everything that I thought it could be: concise, tightly written, absolutely disciplined, and devoid of the dead-tree filler found in much thicker programming books. I cannot recommend this series highly enough for anyone interested in JS. Instead of learning just enough to be dangerous, if you work through this series (preferably open in your browser of choice while writing and running all the code examples in your Developer Tools console), you should emerge with an understanding of closures, coercion, scope, hoisting, and the this identifier.
Up & Going also provides a lot of background instruction for those with limited programming experience in any language. As such, it's a great place to start for those new to software development as well as experienced programmers who want to quickly get up to speed on this crucial piece of the web platform.
June 6, 2016
Don't read and rate this book as a standalone book!!
It's just an intro book for the whole series "YDKJS", presenting main features of the language such as types, functions, scope, the 'this', closures and prototypes. The other books of the series intends to get into the details behind each of these features.
It's a nice introdution to Javascript. The only bad thing about the book is the fact that the author recommends using comments in the code to get it well explained/documented (he says comments should tell "why" and not "what" but it's not what it's shown in code!).
If you feel comfort with JS, you should skip this one and go to the other books of the series.
It's just an intro book for the whole series "YDKJS", presenting main features of the language such as types, functions, scope, the 'this', closures and prototypes. The other books of the series intends to get into the details behind each of these features.
It's a nice introdution to Javascript. The only bad thing about the book is the fact that the author recommends using comments in the code to get it well explained/documented (he says comments should tell "why" and not "what" but it's not what it's shown in code!).
If you feel comfort with JS, you should skip this one and go to the other books of the series.
October 5, 2018
Good intro to the series, it covers the basics well. I have JavaScript experience but found this good for picking up little bits that I was fuzzy on.
It is really just an intro for the rest of the series though. I don't think there's enough here for beginners to get going, but also not enough for more experienced programmers for it to be worth buying it.
I recommend starting with this but plan on carrying on through the rest of the series too.
Types and Grammar makes a good second book to read, even though it is fourth in the series it has some basics important to grasp if you want to find it easier to understand the other books.
It is really just an intro for the rest of the series though. I don't think there's enough here for beginners to get going, but also not enough for more experienced programmers for it to be worth buying it.
I recommend starting with this but plan on carrying on through the rest of the series too.
Types and Grammar makes a good second book to read, even though it is fourth in the series it has some basics important to grasp if you want to find it easier to understand the other books.
November 30, 2019
this was just the beginning of journey of book, like a clear introduction to what we will see in next series.
December 27, 2015
In general, this was a good introduction to both JavaScript and what will be covered in the other books in the 'You Don't Know JS' series. Thank you to the author (Kyle) for dedicating their time to writing these on a relatively small budget (if the Kickstarter is anything to go by), and for making these free to read on GitHub (great for those who want to learn how to code, but can't afford to).
Unfortunately, I take issue with some of the language used in this book.
- "but JS developers seem to stand out from the crowd in the sense of typically not learning very much of the language"
- "Terribly mistaken."
- " just keep following what the crowd say"
Those words suggest quite an elitist attitude. I realise that Kyle has been in this industry many years more than I (I have been doing this for a year and 2 months), and they have experienced way more JavaScript and JavaScript developers than I have. But it strikes me as odd that this entire series is dedicated to encouraging people to learn more about the JavaScript language, whilst simultaneously seeming to demerit those who might be reading the book.
I'm also not sure if a total beginner would learn JavaScript basics by reading this book.
It is a good book, and I do look forward to learning more. I just wish it was a little kinder in parts?
Unfortunately, I take issue with some of the language used in this book.
- "but JS developers seem to stand out from the crowd in the sense of typically not learning very much of the language"
- "Terribly mistaken."
- " just keep following what the crowd say"
Those words suggest quite an elitist attitude. I realise that Kyle has been in this industry many years more than I (I have been doing this for a year and 2 months), and they have experienced way more JavaScript and JavaScript developers than I have. But it strikes me as odd that this entire series is dedicated to encouraging people to learn more about the JavaScript language, whilst simultaneously seeming to demerit those who might be reading the book.
I'm also not sure if a total beginner would learn JavaScript basics by reading this book.
It is a good book, and I do look forward to learning more. I just wish it was a little kinder in parts?
August 2, 2017
أنت لا تعرف جافاسكربت!
لفتني عنوان الكتاب المستفز والمراجعات الكثيرة التي تنصح بقراءة هذه السلسلة ضمن موقع FreeCodeCamp
الجزء الأول بسيط، يتكون من ثلاثة فصول، يتناول الأول مفاهيم برمجية عامة (المتغيرات، الدوال، الحلقات التكرارية إلخ) تصلح كمقدمة إلى البرمجة نفسها لمن لا يملك خلفية مسبقة.
الفصل الثاني هو مقدمة إلى جافاسكربت، وفيه يشرح الكاتب خصائص المفاهيم التي تم شرحها ضمن بيئة جافاسكربت، معظم المفاهيم هنا لم يتم شرحها وتفصيلها كما يجب لأنها تشكّل مواضيع باقي كتب هذه السلسلة
الفصل الأخير يعرض ما سيتم التركيز عليه في الكتب التالية.
هدف السلسلة كما يقول المؤلف تعليم جميع أجزاء ومفاهيم اللغة، وليس فقط الأجزاء التي يراها البعض بأنها مهمة، أو هي ما تلزم لسوق العمل.
يُركّز الكتاب على ذكر نقاط أُسيء فهمها في جافاسكربت على نطاق واسع، أو أسيء استعمالها، ولهذا يختتم الكتاب بقوله: نحن لا نعرف جافاسكربت، لكننا سنعرفها!
لفتني عنوان الكتاب المستفز والمراجعات الكثيرة التي تنصح بقراءة هذه السلسلة ضمن موقع FreeCodeCamp
الجزء الأول بسيط، يتكون من ثلاثة فصول، يتناول الأول مفاهيم برمجية عامة (المتغيرات، الدوال، الحلقات التكرارية إلخ) تصلح كمقدمة إلى البرمجة نفسها لمن لا يملك خلفية مسبقة.
الفصل الثاني هو مقدمة إلى جافاسكربت، وفيه يشرح الكاتب خصائص المفاهيم التي تم شرحها ضمن بيئة جافاسكربت، معظم المفاهيم هنا لم يتم شرحها وتفصيلها كما يجب لأنها تشكّل مواضيع باقي كتب هذه السلسلة
الفصل الأخير يعرض ما سيتم التركيز عليه في الكتب التالية.
هدف السلسلة كما يقول المؤلف تعليم جميع أجزاء ومفاهيم اللغة، وليس فقط الأجزاء التي يراها البعض بأنها مهمة، أو هي ما تلزم لسوق العمل.
يُركّز الكتاب على ذكر نقاط أُسيء فهمها في جافاسكربت على نطاق واسع، أو أسيء استعمالها، ولهذا يختتم الكتاب بقوله: نحن لا نعرف جافاسكربت، لكننا سنعرفها!
November 25, 2015
A modern replacement of the Jumpstart JavaScript book by Sitepoint.
Kyle introduces JS and a few ES6 features you need to know from the start. Nothing too dragged out. It's actually very short and concise.
Also nothing complex, but mandatory to know before going deep. Last chapter is a handy reference to the other books for YDKJS and short intro about any of the given books.
Only reason the book gets 4 stars is because it lacks exercises that might help readers practice what they learn. It's not a deal breaker, but it makes the reader learn the author's point better by practice.
Kyle introduces JS and a few ES6 features you need to know from the start. Nothing too dragged out. It's actually very short and concise.
Also nothing complex, but mandatory to know before going deep. Last chapter is a handy reference to the other books for YDKJS and short intro about any of the given books.
Only reason the book gets 4 stars is because it lacks exercises that might help readers practice what they learn. It's not a deal breaker, but it makes the reader learn the author's point better by practice.
January 29, 2019
Fool enough to start reading this late but clever enough to start at least. First part gives a summary on the different aspect of JS and I hope the latter books will explain those features completely.
July 11, 2016
This book seems to me too simple for other programmers trying to get into JS and too difficult for beginners. I feel like it's trying to be a happy medium between the two.
However, I agree that a lot of JS users do not really know the core concepts of what the language has to offer and this book.
I would recommend this book to JS users who already know a bit about JS. It's a good entry into the other books in the series though, so three ⭐️ for that.
However, I agree that a lot of JS users do not really know the core concepts of what the language has to offer and this book.
I would recommend this book to JS users who already know a bit about JS. It's a good entry into the other books in the series though, so three ⭐️ for that.
April 4, 2018
Noy a bad intro to the series, the author tends to get a bit verbose, but I guess that's to be expected. However, this has clarified some key concepts and set the stage for the remaining books.
April 27, 2018
Short and packed with knowledge! This one is basically an introduction to the series but I still learned a lot. Looking forward to the rest of the books!
January 14, 2018
Książka otwiera całkiem fajną serię na temat tajników JavaScriptu. Sama w sobie nie wnosi jednak zbyt dużo poza dość pobieżnym przejściem przez różne tematy po to, by zaznaczyć które z nich zostaną rozwinięte w poszczególnych częściach serii. Zatem jeśli ktoś cokolwiek o JavaScripcie wie, okrutnie się wynudzi czytając ją. Natomiast dla początkujących jako start przed czytaniem bardziej skomplikowanych tematów w kolejnych książkach jest jak najbardziej w porządku. Forma książki jest dość konkretna i krótka dzięki czemu nie mierzymy się już na starcie z niewyobrażalną ilością stron do przyswojenia. Zarówno tutaj jak i w pozostałych częściach serii forma jest krótka, bo liczy niecałe 100 stron więc nie ma efektu zniechęcenia już na samym początku. Polecam:)
March 6, 2020
I quote from the writer:
" The YDKJS series is dedicated to the proposition that all JS develop�
ers can and should learn all of the parts of this great language. No
person’s opinion, no framework’s assumptions, and no project’s
deadline should be the excuse for why you never learn and deeply
understand JavaScript. "
" The YDKJS series is dedicated to the proposition that all JS develop�
ers can and should learn all of the parts of this great language. No
person’s opinion, no framework’s assumptions, and no project’s
deadline should be the excuse for why you never learn and deeply
understand JavaScript. "
January 9, 2018
Perfect basic coverage. Highly recommended for any js developer
May 25, 2018
Great introductory book to prepare for the rest of the books in the series. Learned a few new things!
March 23, 2021
Αρκετά καλό, εισαγωγικό μέρος της σειράς. Σε γενικές γραμμές τα λέει ωραία και κατανοητά, αν και πολλές φορές από εκεί που διαβάζεις Λόλα να ένα μήλο σε πάει σε πυρηνική φυσική στην αμέσως επόμενη γραμμή. Φοβάμαι λίγο τι θα δω στα επόμενα, οπότε 3 συντηρητικά αστεράκια για την ��ρα και βλέπουμε.
August 14, 2019
Nice intro to JS and what follows in the next series of the book.
February 28, 2019
Good introduction to JS. Although this book was just an overview of the following books, it already gave me much insight on what I was missing with understanding JavaScript fundamentally. It provides clarity of the weird quirks of JavaScript by taking its time to explain why JavaScript works the way that it does.
March 25, 2019
I have had preliminary knowledge of JS before reading this book, so it was easier understanding most of the concepts being discussed in the book.. i'd always recommend to any other newbie trying to make sense of JavaScript. Great read!
March 13, 2019
Got this from for and recommended by a friend. Found out the book not really useful if you're a seasonal programmer that already familiar with Javascript, this book feel more like an intro to promote another books in the series.
There are 3 chapters in this book. The first 2 chapters is for person that didn't have programming experience before and if it you, i would also not recommend this book as the way how to programming explained in this books is not how we program in real world.
E.g: make javascript code in browser console. I would not recommend to do that if you're new. Rather than that, i would recommend what we do in real world programming. We create a js file and have js file load into browser via HTML. This will help new programmer to understand that after they know how to code, they know how to apply it.
Then Chapter 3 is more like an intro, a theory that didn't explain anything. And to know in deep, we should purchase the book in another series.
Summary:
I'm not sure this books intended for which programmer level.
If it for newcommer, i will prefer to teach programming by how to apply the knowledge rather than knowing what it is.
If it for seasonal programmer, there should be more advanced content which it not covered in detail in this books.
There are 3 chapters in this book. The first 2 chapters is for person that didn't have programming experience before and if it you, i would also not recommend this book as the way how to programming explained in this books is not how we program in real world.
E.g: make javascript code in browser console. I would not recommend to do that if you're new. Rather than that, i would recommend what we do in real world programming. We create a js file and have js file load into browser via HTML. This will help new programmer to understand that after they know how to code, they know how to apply it.
Then Chapter 3 is more like an intro, a theory that didn't explain anything. And to know in deep, we should purchase the book in another series.
Summary:
I'm not sure this books intended for which programmer level.
If it for newcommer, i will prefer to teach programming by how to apply the knowledge rather than knowing what it is.
If it for seasonal programmer, there should be more advanced content which it not covered in detail in this books.
August 31, 2016
This was an amazing little book, easy to read and understand. I found it while reading my feed on Quora and decided to give it a try.
It demystifies things like coercion, closures, hoisting and the this identifier. This book whets your appetite into learning all parts of JavaScript and not just the good parts.
I can't wait to read the whole series!
It demystifies things like coercion, closures, hoisting and the this identifier. This book whets your appetite into learning all parts of JavaScript and not just the good parts.
I can't wait to read the whole series!
January 29, 2019
This is not a book to learn any JS, this is just an intro to tell you what's the language about and constantly refers you to all the other books of this series. It touches simple topics as well as pretty complex topics, making it not suitable for beginners nor for experts. I would never recommend this book.
September 20, 2015
Nice intro into series. While staying at a basic and fundamental level, this book gives a nice inspiration on what series of You Don't Know JS will bring to the table.
Very excited to read other books of this series.
Very excited to read other books of this series.
June 13, 2016
It is awesome book for novice to professional JS developers. It's main focus on why? It isn't how. You can find good tricks about JavaScript.
June 22, 2016
In general, this book is a good JavaScript book.
personally, I didn't like the way Kyle take about JavaScript The Good Parts book.
anyway, I recommend this book to anyone beginner in javascript.
personally, I didn't like the way Kyle take about JavaScript The Good Parts book.
anyway, I recommend this book to anyone beginner in javascript.
May 28, 2016
I loved his approach in handling the subjects :)
June 30, 2017
CONTEXT: JavaScript is a strange language by some standards, yet is inarguably a critical piece of knowledge for anyone programming for the web. This book is one of 6, but you could consider it to be the intro to the REAL set of FIVE books. If you are not already a strong JS developer then you will benefit by reading this first book because it lays out the issues all in one place. But do NOT expect any good answers to the issues (then you'll appreciate the insights that you do get). If you are familiar with core JavaScript issues, skip this and read the 5. I'll return to this review after reading at least one of the others. Keep in mind that this first (of the six) is free.
I debated on this rating because 1. the book was helpful as a survey of issues, yet 2. it's clearly a teaser for the series. If I consider it to be a list of things that I'd want to know better, then it met the goal well and I could justify a higher rating. If I consider it to be a measurement of knowledge I actually gained and can apply, it fell very short.
FORGET about the rating... the series appears to be very insightful and has a trait that I appreciate; a strong stance on how to view/use the language while presenting other sides (even if not fully). Even if you think the author's position is too strong, you gain knowledge in how to use the features and make up your own mind about the philosophical sides. I really appreciated this, but I did not gain the knowledge I hoped. So I bought one more. We'll see how I like that.
I debated on this rating because 1. the book was helpful as a survey of issues, yet 2. it's clearly a teaser for the series. If I consider it to be a list of things that I'd want to know better, then it met the goal well and I could justify a higher rating. If I consider it to be a measurement of knowledge I actually gained and can apply, it fell very short.
FORGET about the rating... the series appears to be very insightful and has a trait that I appreciate; a strong stance on how to view/use the language while presenting other sides (even if not fully). Even if you think the author's position is too strong, you gain knowledge in how to use the features and make up your own mind about the philosophical sides. I really appreciated this, but I did not gain the knowledge I hoped. So I bought one more. We'll see how I like that.
December 9, 2018
Very good, short introductory book. The author seems like he's really had enough of people only vaguely understanding Javascript, and he's dedicated to teach us the s*&%t out of JS :D It's fun, I appreciate this serious, non-superficial way of approaching teaching.
I plan to read the entire series, so I started with the intro book. It was fun, and I'm looking forward to learning the hard parts.
Also, now I understand why "asdf" does not equal, and is neither greater or smaller then 3. Still, I prefer Python's more strongly typed nature. Really, strong typing just prevents bugs.
Where my opinion diverges from the author's is in that he does not seem to acknowledge too explicitly that the language indeed has flaws, even if those flaws have workarounds.
I'd like to hear more of the "ok, this feature sucks, it was built in haste and without data, new people will be confused by it, no matter how much JS the seniors in the team understand...and that's mostly the reason we should avoid using it".
Recommended!
I plan to read the entire series, so I started with the intro book. It was fun, and I'm looking forward to learning the hard parts.
Also, now I understand why "asdf" does not equal, and is neither greater or smaller then 3. Still, I prefer Python's more strongly typed nature. Really, strong typing just prevents bugs.
Where my opinion diverges from the author's is in that he does not seem to acknowledge too explicitly that the language indeed has flaws, even if those flaws have workarounds.
I'd like to hear more of the "ok, this feature sucks, it was built in haste and without data, new people will be confused by it, no matter how much JS the seniors in the team understand...and that's mostly the reason we should avoid using it".
Recommended!
December 18, 2018
Trata dos conceitos básicos, afinal é só a introdução à Série, mas gostei da filosofia e fiquei curioso para ler os demais:
<< This You Don’t Know JS series offers a contrary challenge: learn and deeply understand all of JavaScript, even and especially “The Tough Parts.�
Here, we address head-on the tendency of JS developers to learn just enough to get by, without ever forcing themselves to learn exactly how and why the language behaves the way it does. Furthermore, we eschew the common advice to retreat when the road gets rough. I am not content, nor should you be, at stopping once something just works and not really knowing why. I gently challenge you to journey down that bumpy “road less traveled� and embrace all that JavaScript is and can do. With that knowledge, no technique, no framework, and no popular buzzword acronym of the week will be beyond your understanding. >>
<< This You Don’t Know JS series offers a contrary challenge: learn and deeply understand all of JavaScript, even and especially “The Tough Parts.�
Here, we address head-on the tendency of JS developers to learn just enough to get by, without ever forcing themselves to learn exactly how and why the language behaves the way it does. Furthermore, we eschew the common advice to retreat when the road gets rough. I am not content, nor should you be, at stopping once something just works and not really knowing why. I gently challenge you to journey down that bumpy “road less traveled� and embrace all that JavaScript is and can do. With that knowledge, no technique, no framework, and no popular buzzword acronym of the week will be beyond your understanding. >>
June 1, 2019
This is the first book in the series of five. It introduces some basic programming/JavaScript concepts (loops, conditions, scope...), some intermediate/advanced concepts (closure, prototypes...), and prepares you for going deeper into these ideas in later books.
While it does a great job explaining basic stuff I had a hard time getting even the slightest idea of what he's talking about when he moved on to closure, modules, and prototypes, but it's not so big of a deal, because he kinda wanted just to mention them before getting into details later.
This series was great so far, and I understand why many web developers recommend it. Ebook version can be found on Github legally for free:
While it does a great job explaining basic stuff I had a hard time getting even the slightest idea of what he's talking about when he moved on to closure, modules, and prototypes, but it's not so big of a deal, because he kinda wanted just to mention them before getting into details later.
This series was great so far, and I understand why many web developers recommend it. Ebook version can be found on Github legally for free:
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