Merge pull request #2 from iliakan/master

Repo Update 4-Aug, 2018

Author: aniketkudale

Diff for: 1-js/02-first-steps/01-hello-world/article.md

@@ -47,7 +47,7 @@ The `<script>` tag has a few attributes that are rarely used nowadays, but we ca
 
  The `type` attribute: <code>&lt;script <u>type</u>=...&gt;</code>
 
- : The old standard HTML4 required a script to have a type. Usually it was `type="text/javascript"`. The modern HTML standard assumes this `type` by default. No attribute is required.
+ : The old standard HTML4 required a script to have a type. Usually it was `type="text/javascript"`. It's not required any more. Also, the modern standard totally changed the meaning of this attribute. Now it can be used for Javascript modules. But that's an advanced topic, but we'll talk about modules later in another part of the tutorial. 
 
  The `language` attribute: <code>&lt;script <u>language</u>=...&gt;</code>
   : This attribute was meant to show the language of the script. As of now, this attribute makes no sense, the language is JavaScript by default. No need to use it.

Diff for: 1-js/02-first-steps/04-variables/article.md

@@ -247,7 +247,7 @@ const myBirthday = '18.04.1982';
 myBirthday = '01.01.2001'; // error, can't reassign the constant!
 ```
 
-When a programmer is sure that the variable should never change, he can use `const` to guarantee it, and also to clearly show that fact to everyone.
+When a programmer is sure that the variable should never change, they can use `const` to guarantee it, and also to clearly show that fact to everyone.
 
 
 ### Uppercase constants

Diff for: 1-js/02-first-steps/12-while-for/6-repeat-until-correct/task.md

@@ -4,7 +4,7 @@ importance: 5
 
 # Repeat until the input is correct
 
-Write a loop which prompts for a number greater than `100`. If the visitor enters another number -- ask him to input again.
+Write a loop which prompts for a number greater than `100`. If the visitor enters another number -- ask them to input again.
 
 The loop must ask for a number until either the visitor enters a number greater than `100` or cancels the input/enters an empty line.
 

Diff for: 1-js/02-first-steps/16-javascript-specials/article.md

@@ -103,15 +103,15 @@ More in: <info:variables> and <info:types>.
 We're using a browser as a working environment, so basic UI functions will be:
 
 [`prompt(question[, default])`](mdn:api/Window/prompt)
-: Ask a `question`, and return either what the visitor entered or `null` if he pressed "cancel".
+: Ask a `question`, and return either what the visitor entered or `null` if they pressed "cancel".
 
 [`confirm(question)`](mdn:api/Window/confirm)
 : Ask a `question` and suggest to choose between Ok and Cancel. The choice is returned as `true/false`.
 
 [`alert(message)`](mdn:api/Window/alert)
 : Output a `message`.
 
-All these functions are *modal*, they pause the code execution and prevent the visitor from interacting with the page until he answers.
+All these functions are *modal*, they pause the code execution and prevent the visitor from interacting with the page until they answer.
 
 For instance:
 

Diff for: 1-js/03-code-quality/04-ninja-code/article.md

@@ -34,7 +34,7 @@ i = i ? i < 0 ? Math.max(0, len + i) : i : 0;
 
 Cool, right? If you write like that, the developer who comes across this line and tries to understand what is the value of `i` is going to have a merry time. Then come to you, seeking for an answer.
 
-Tell him that shorter is always better. Initiate him into the paths of ninja.
+Tell them that shorter is always better. Initiate them into the paths of ninja.
 
 ## One-letter variables
 
@@ -45,11 +45,11 @@ completed.
 
 Another way to code faster is to use single-letter variable names everywhere. Like `a`, `b` or `c`.
 
-A short variable disappears in the code like a real ninja in the forest. No one will be able to find it using "search" of the editor. And even if someone does, he won't be able to "decipher" what the name `a` or `b` means.
+A short variable disappears in the code like a real ninja in the forest. No one will be able to find it using "search" of the editor. And even if someone does, they won't be able to "decipher" what the name `a` or `b` means.
 
 ...But there's an exception. A real ninja will never use `i` as the counter in a `"for"` loop. Anywhere, but not here. Look around, there are many more exotic letters. For instance, `x` or `y`.
 
-An exotic variable as a loop counter is especially cool if the loop body takes 1-2 pages (make it longer if you can). Then if someone looks deep inside the loop, he won't be able to quickly figure out that the variable named `x` is the loop counter.
+An exotic variable as a loop counter is especially cool if the loop body takes 1-2 pages (make it longer if you can). Then if someone looks deep inside the loop, they won't be able to quickly figure out that the variable named `x` is the loop counter.
 
 ## Use abbreviations
 
@@ -153,7 +153,7 @@ function ninjaFunction(elem) {
 }
 ```
 
-A fellow programmer who wants to work with `elem` in the second half of the function will be surprised... Only during the debugging, after examining the code he will find out that he's working with a clone!
+A fellow programmer who wants to work with `elem` in the second half of the function will be surprised... Only during the debugging, after examining the code they will find out that he's working with a clone!
 
 Deadly effective even against an experienced ninja. Seen in code regularly.
 
@@ -204,7 +204,7 @@ There are functions that look like they don't change anything. Like `isReady()`,
 
 **A really beautiful trick is to add a "useful" action to them, besides the main task.**
 
-The expression of dazed surprise on the face of your colleague when he sees a function named `is..`, `check..` or `find...` changing something -- will definitely broaden your boundaries of reason.
+The expression of dazed surprise on the face of your colleague when they see a function named `is..`, `check..` or `find...` changing something -- will definitely broaden your boundaries of reason.
 
 **Another way to surprise is to return a non-standard result.**
 
@@ -228,7 +228,7 @@ Additional actions should not be obvious from the function name. A true ninja co
 
 **Joining several actions into one protects your code from reuse.**
 
-Imagine, another developer wants only to check the email, and not output any message. Your function  `validateEmail(email)` that does both will not suit him. So he won't break your meditation by asking anything about it.
+Imagine, another developer wants only to check the email, and not output any message. Your function  `validateEmail(email)` that does both will not suit them. So they won't break your meditation by asking anything about it.
 
 ## Summary
 

Diff for: 1-js/03-code-quality/06-polyfills/article.md

@@ -19,7 +19,7 @@ Here Babel comes to the rescue.
 
 Actually, there are two parts in Babel:
 
-1. First, the transpiler program, which rewrites the code. The developer runs it on his own computer. It rewrites the code into the older standard. And then the code is delivered to the website for users. Modern project build system like [webpack](http://webpack.github.io/) or [brunch](http://brunch.io/) provide means to run transpiler automatically on every code change, so that doesn't involve any time loss from our side.
+1. First, the transpiler program, which rewrites the code. The developer runs it on their own computer. It rewrites the code into the older standard. And then the code is delivered to the website for users. Modern project build system like [webpack](http://webpack.github.io/) or [brunch](http://brunch.io/) provide means to run transpiler automatically on every code change, so that doesn't involve any time loss from our side.
 
 2. Second, the polyfill.
 

Diff for: 1-js/05-data-types/02-number/article.md

@@ -201,7 +201,7 @@ Strange! What is it then if not `0.3`?
 alert( 0.1 + 0.2 ); // 0.30000000000000004
 ```
 
-Ouch! There are more consequences than an incorrect comparison here. Imagine you're making an e-shopping site and the visitor puts `$0.10` and `$0.20` goods into his chart. The order total will be `$0.30000000000000004`. That would surprise anyone.
+Ouch! There are more consequences than an incorrect comparison here. Imagine you're making an e-shopping site and the visitor puts `$0.10` and `$0.20` goods into their chart. The order total will be `$0.30000000000000004`. That would surprise anyone.
 
 But why does this happen?
 

Diff for: 1-js/05-data-types/03-string/article.md

@@ -451,7 +451,7 @@ Let's recap these methods to avoid any confusion:
 ```smart header="Which one to choose?"
 All of them can do the job. Formally, `substr` has a minor drawback: it is described not in the core JavaScript specification, but in Annex B, which covers browser-only features that exist mainly for historical reasons. So, non-browser environments may fail to support it. But in practice it works everywhere.
 
-The author finds himself using `slice` almost all the time.
+The author finds themself using `slice` almost all the time.
 ```
 
 ## Comparing strings

Diff for: 1-js/05-data-types/04-array/article.md

@@ -369,7 +369,7 @@ It's rarely used, because square brackets `[]` are shorter. Also there's a trick
 
 If `new Array` is called with a single argument which is a number, then it creates an array *without items, but with the given length*.
 
-Let's see how one can shoot himself in the foot:
+Let's see how one can shoot themself in the foot:
 
 ```js run
 let arr = new Array(2); // will it create an array of [2] ?

Diff for: 1-js/05-data-types/07-map-set-weakmap-weakset/article.md

@@ -47,7 +47,7 @@ For instance:
 ```js run
 let john = { name: "John" };
 
-// for every user, let's store his visits count
+// for every user, let's store their visits count
 let visitsCountMap = new Map();
 
 // john is the key for the map
@@ -332,7 +332,7 @@ That's useful for situations when we have a main storage for the objects somewhe
 
 Let's look at an example.
 
-For instance, we have code that keeps a visit count for each user. The information is stored in a map: a user is the key and the visit count is the value. When a user leaves, we don't want to store his visit count anymore.
+For instance, we have code that keeps a visit count for each user. The information is stored in a map: a user is the key and the visit count is the value. When a user leaves, we don't want to store their visit count anymore.
 
 One way would be to keep track of leaving users and clean up the storage manually:
 

Diff for: 1-js/06-advanced-functions/09-call-apply-decorators/04-throttle/task.md

@@ -22,7 +22,7 @@ So we'll assign `throttle(update, 100)` as the function to run on each mouse mov
 
 Visually, it will look like this:
 
-1. For the first mouse movement the decorated variant passes the call to `update`. That's important, the user sees our reaction to his move immediately.
+1. For the first mouse movement the decorated variant passes the call to `update`. That's important, the user sees our reaction to their move immediately.
 2. Then as the mouse moves on, until `100ms` nothing happens. The decorated variant ignores calls.
 3. At the end of `100ms` -- one more `update` happens with the last coordinates. 
 4. Then, finally, the mouse stops somewhere. The decorated variant waits until `100ms` expire and then runs `update` runs with last coordinates. So, perhaps the most important, the final mouse coordinates are processed.

Diff for: 1-js/07-object-oriented-programming/01-property-descriptors/article.md

@@ -118,7 +118,7 @@ user.name = "Pete"; // Error: Cannot assign to read only property 'name'...
 */!*
 ```
 
-Now no one can change the name of our user, unless he applies his own `defineProperty` to override ours.
+Now no one can change the name of our user, unless they apply their own `defineProperty` to override ours.
 
 Here's the same operation, but for the case when a property doesn't exist:
 

Diff for: 1-js/07-object-oriented-programming/03-prototype-inheritance/4-hamster-proto/solution.md

@@ -44,7 +44,7 @@ alert( lazy.stomach ); // <nothing>
 
 Now all works fine, because `this.stomach=` does not perform a lookup of `stomach`. The value is written directly into `this` object.
 
-Also we can totally evade the problem by making sure that each hamster has his own stomach:
+Also we can totally evade the problem by making sure that each hamster has their own stomach:
 
 ```js run
 let hamster = {

Diff for: 1-js/07-object-oriented-programming/09-class/animal-rabbit-extends.png renamed to 1-js/07-object-oriented-programming/10-class-inheritance/animal-rabbit-extends.png

@@ -194,7 +194,7 @@ You can find more detailed information about JSON in the <info:json> chapter.
 
 Should we be satisfied with that? Of course, not!
 
-This way, if something's wrong with the data, the visitor will never know that (unless he opens developer console). And people really don't like when something "just dies" without any error message.
+This way, if something's wrong with the data, the visitor will never know that (unless they open the developer console). And people really don't like when something "just dies" without any error message.
 
 Let's use `try..catch` to handle the error:
 
@@ -575,7 +575,7 @@ The information from this section is not a part of the core JavaScript.
 
 Let's imagine we've got a fatal error outside of `try..catch`, and the script died. Like a programming error or something else terrible.
 
-Is there a way to react on such occurrences? We may want to log the error, show something to the user (normally he doesn't see error messages) etc.
+Is there a way to react on such occurrences? We may want to log the error, show something to the user (normally they don't see error messages) etc.
 
 There is none in the specification, but environments usually provide it, because it's really useful. For instance, Node.JS has [process.on('uncaughtException')](https://nodejs.org/api/process.html#process_event_uncaughtexception) for that. And in the browser we can assign a function to special [window.onerror](mdn:api/GlobalEventHandlers/onerror) property. It will run in case of an uncaught error.
 

Diff for: 1-js/07-object-oriented-programming/09-class/[email protected] renamed to 1-js/07-object-oriented-programming/10-class-inheritance/[email protected]

@@ -4,7 +4,7 @@ importance: 5
 
 # Catch links in the element
 
-Make all links inside the element with `id="contents"` ask the user if he really wants to leave. And if he doesn't then don't follow.
+Make all links inside the element with `id="contents"` ask the user if they really want to leave. And if they don't then don't follow.
 
 Like this:
 

Diff for: 1-js/08-error-handling/1-try-catch/article.md

@@ -175,7 +175,7 @@ Now if you double-click on "Unselectable", it doesn't get selected. Seems to wor
 
 ...But there is a potential problem! The text became truly unselectable. Even if a user starts the selection from "Before" and ends with "After", the selection skips "Unselectable" part. Do we really want to make our text unselectable?
 
-Most of time, we don't. A user may have valid reasons to select the text, for copying or other needs. That may be inconvenient if we don't allow him to do it. So this solution is not that good.
+Most of time, we don't. A user may have valid reasons to select the text, for copying or other needs. That may be inconvenient if we don't allow them to do it. So this solution is not that good.
 
 What we want is to prevent the selection on double-click, that's it.
 

Diff for: 2-ui/2-events/04-default-browser-action/2-catch-link-navigation/task.md

@@ -10,7 +10,7 @@ Each event may be useful:
 
 - `DOMContentLoaded` event -- DOM is ready, so the handler can lookup DOM nodes, initialize the interface.
 - `load` event -- additional resources are loaded, we can get image sizes (if not specified in HTML/CSS) etc.
-- `beforeunload/unload` event -- the user is leaving: we can check if the user saved the changes and  ask him whether he really wants to leave.
+- `beforeunload/unload` event -- the user is leaving: we can check if the user saved the changes and ask them whether they really want to leave.
 
 Let's explore the details of these events.
 

Diff for: 2-ui/3-event-details/1-mouse-events-basics/article.md

@@ -6,7 +6,7 @@ importance: 5
 
 Write a function that shows a tooltip over an element only if the visitor moves the mouse *over it*, but not *through it*.
 
-In other words, if the visitor moves the mouse on the element and stopped -- show the tooltip. And if he just moved the mouse through fast, then no need, who wants extra blinking?
+In other words, if the visitor moves the mouse on the element and stopped -- show the tooltip. And if they just moved the mouse through fast, then no need, who wants extra blinking?
 
 Technically, we can measure the mouse speed over the element, and if it's slow then we assume that it comes "over the element" and show the tooltip, if it's fast -- then we ignore it.
 

Diff for: 2-ui/3-event-details/10-onload-ondomcontentloaded/article.md

@@ -23,7 +23,7 @@
         // JavaScript does not get the "keyup" event
         // and pressed set will keep assuming that the key is pressed
         // so, to evade "sticky" keys, we reset the status
-        // if the user wants to run the hotkey again - let him press all keys again
+        // if the user wants to run the hotkey again - let them press all keys again
         pressed.clear();
 
         func();

Diff for: 2-ui/3-event-details/3-mousemove-mouseover-mouseout-mouseenter-mouseleave/2-hoverintent/task.md

@@ -4,7 +4,7 @@ importance: 4
 
 # Load visible images
 
-Let's say we have a slow-speed client and want to save his mobile traffic.
+Let's say we have a slow-speed client and want to save their mobile traffic.
 
 For that purpose we decide not to show images immediately, but rather replace them with placeholders, like this:
 

Diff for: 2-ui/3-event-details/5-keyboard-events/2-check-sync-keydown/solution.view/index.html

@@ -6,7 +6,7 @@ importance: 5
 
 Create a function `showPrompt(html, callback)` that shows a form with the message `html`, an input field and buttons `OK/CANCEL`.
 
-- A user should type something into a text field and press `key:Enter` or the OK button, then `callback(value)` is called with the value he entered.
+- A user should type something into a text field and press `key:Enter` or the OK button, then `callback(value)` is called with the value they entered.
 - Otherwise if the user presses `key:Esc` or CANCEL, then `callback(null)` is called.
 
 In both cases that ends the input process and removes the form.

Diff for: 2-ui/3-event-details/8-onscroll/3-load-visible-img/task.md

@@ -176,7 +176,7 @@ Still, there are some things that can be done.
 For instance:
 
 - When we open a popup, it's might be a good idea to run a `newWindow.focus()` on it. Just in case, for some OS/browser combinations it ensures that the user is in the new window now.
-- If we want to track when a visitor actually uses our web-app, we can track `window.onfocus/onblur`. That allows us to suspend/resume in-page activities, animations etc. But please note that the `blur` event means that the visitor switched out from the window, but he still may observe it. The window is in the background, but still may be visible.
+- If we want to track when a visitor actually uses our web-app, we can track `window.onfocus/onblur`. That allows us to suspend/resume in-page activities, animations etc. But please note that the `blur` event means that the visitor switched out from the window, but they still may observe it. The window is in the background, but still may be visible.
 
 ## Summary