When pressing right key or "->" symbol and a new chapter is loaded, pressing up/down keys do not work (this is, you cannot scroll up/down the chapter text with the keyboard). For it to work I need to click with the mouse on the chapter so it gets the focus.

I suggest manually firing the "focus" event on the chapter container after loaded.

In 6.2 Higher Order Functions, could you tell the difference compare to javascript closure?

For me this so called 'Higher order functions' is exactly how I understand 'closure'. If I'm right, please add 'this is what other people called closure' at the end of this section. It surely will clarify the misunderstanding.

@SamyPesse @AaronO Thank you

just pointing it out

in loops you explain in the beginning of the chapter using arraus access, when you haven't showed me an array before

I'm loving the simplicity of the book I'm just pointing it out

k

I have now finished a list of exercises in JS, can I add it here, in order to contribute and make your repository fuller?

The following in console:

track exercise.submit
Uncaught TypeError: Object [object Array] has no method 'track'
r
(anonymous function)
jQuery.event.dispatch
m.handle

upon every click of the Submit button in any Exercise. Feedback about whether or not the exercise was completed correctly does not show up.

It would be nice to have a separate CSS template / button option for exporting books to PDF :)

The book is really good and easy to understand.I would become even more awesome if you could add another chapter on how implement Javascript and make real world web applications.Just a brief idea to get the reader started.On how to get the best out of Javascript.

Clicking in the left-superior icon is driving to this page: https://github.com/null

I think there's the same behavior in "How to Make a Computer Operating System" gitbook

please add new problems of linked list

Hello, Myself Siyona Lodha!
I wanted to contribute to your project for my college open source lab.
Can you please assign me some tasks and give me an opportunity to become a contributor?

Thank you,
Waiting for a positive response :)

I can't figure out, why the (.." "..) is needed in ( firstName + " " + Last name )

Marketing System Evolution Of Platform

while learning JS, i ran into a small issue and im stuck . Any help rendered would be appreciated

First block of code. It should be "This is an integer" instead of "This is a integer".

Thanks for the book :)

Hi,

the greater than and less than unicodes are not rendered properly on the documentation website.

The introduction in README.md should be larger and better.

On quite a few of the pages, various symbols ( ` < > & ) are showing up as HTML entities in the explanatory and exercise text.

An example from 4.3 on the website:

• x > a: is x bigger than a?
• x < a: is x less than a?

Which looks as expected on github:

• x > a: is x bigger than a?
• x < a: is x less than a?

Substrings hasn't done?

I'm attempting to write an experiment that will require 4 basic parts: a fixation cross, an instruction, an experimental stimulus, and a rating scale. I switched the language to JavaScript from JSPsych per the request of my instructor, but I'm now having trouble translating certain plugins from the JSPsych library to basic JavaScript code.
Each of the parts listed above will need a trial duration. For example the fixation cross needs to be shown for 2 seconds, the instructions for 4 seconds, and so on. I'm pretty sure I can loop through the trials, I just need help with how to set up a variable to show the pictures for a specific amount of time.
Thanks!

I'd propose to add more information on JS arrays.

1. push, shift, pull etc.
2. Sparse arrays like [1,2,,,,,,,4,0,,,2].
3. Methods on iterating over arrays: forEach, some, filter etc.

Syntax on the array introduction needs to be changed from [] to {} for the example. Exercises also need line breaks fixed.

For loop:

Create using a for-loop a variable named message which equals the concatenation of integers (1, 2, 3, ...) from 0 to 100.

The first time I did this, I assumed that it wanted number 0 to 100 (inclusive):

for (var i = 0; i <= 100; i++) {
    /* code */
}

Which has a <= sign so it would include 100, which was marked as incorrect, since the for loop uses <100, which would stop at 99. The words seem to conflict with what the code is actually producing.

While loop:

Create using a while-loop a variable named message which equals the concatenation of integers (1, 2, 3, ...) as long as its length (message.length) is inferior to 100.

I would use "less than 100" rather than "inferior to 100", since I feel like less than creates a link between the words and the operator (as we did earlier with ands and ors).

For both of these, I would also start replace "integers (1, 2, 3, ...)" with "integers (0, 1, 2, ...), since both of these examples start with 0, and the last one doesn't indicate one should start at 0 rather than at 1.

Overall, this is an awesome project and I hope to see more programming books written in the same style! Keep up the good work :)

I think, that`s a good idea to add information about some useful ECMAScript 6 features, such as: template literals/string interpolation, arrow function, modules etc.

Why does the example code use === to compare string variables to static strings, but the code used to quiz the user uses ==? this hasn't been brought up before this exercise I don't think.

The notion of equality should be introduced in the algebra section (2), teaching the use of === over ==. Currently, the single equals = is used to explain algebra, which, though maybe less confusing to a newbie programmer, is syntactically wrong and semantically confusing.

Later in the book, after discussing typing, you should discuss the problems with using == over ===. In the current version of the book, at section (4.1) you implicitly use ===, but in the example at the bottom, the default is to use ==! This is very confusing and glosses over a very real problem with Javascript.

The "Advanced Operators" exercise asks for "the modulus of the decremented value of x by 3". Since x is initially 10, I would assume that "the decremented value of x" would be 9 -- but my solution of var c = --x % 3; was rejected. The accepted answer was var c = x-- % 3;, which computes the modulus of the undecremented value of x.

I suggest rewording the question (though I haven't thought just how).

There is a typo in comments below:
// calling buildProcessor returns a functoin which is called with a list input

add dark mode functionality

It's not clear to me what is being asked for in the HOF exercise. A reference is made to a function named add that doesn't exist; I assume this is a typo and that it should be referring to the function named add1. The bigger question is what is meant by the opposite value of that returned by add1? Minus 1?

I'm using Safari 6.1.2. The interactive buttons don't seem to be responding? Strange since the Next button works fine, and I can type in the box for the exercises, no problems with any of that.

Text has "function f" and example has "function func"

The example that explains the difference between the mutable and immutable JS values is unclear for a beginner.
In the example you have described the primitive value as mutable, it will become more clear if you'd describe in the example the immutability of primitive values.