Merge branch 'master' of github.com:javascript-tutorial/en.javascript.info into sync-34a80e70

Author: iliakan

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: iliakan

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

@@ -88,16 +88,16 @@ In older scripts, you may also find another keyword: `var` instead of `let`:
 *!*var*/!* message = 'Hello';
 ```
 
-The `var` keyword is *almost* the same as `let`. It also declares a variable, but in a slightly different, "old-school" way.
+The `var` keyword is *almost* the same as `let`. It also declares a variable but in a slightly different, "old-school" way.
 
-There are subtle differences between `let` and `var`, but they do not matter for us yet. We'll cover them in detail in the chapter <info:var>.
+There are subtle differences between `let` and `var`, but they do not matter to us yet. We'll cover them in detail in the chapter <info:var>.
 ````
 
 ## A real-life analogy
 
 We can easily grasp the concept of a "variable" if we imagine it as a "box" for data, with a uniquely-named sticker on it.
 
-For instance, the variable `message` can be imagined as a box labeled `"message"` with the value `"Hello!"` in it:
+For instance, the variable `message` can be imagined as a box labelled `"message"` with the value `"Hello!"` in it:
 
 ![](variable.svg)
 
@@ -198,14 +198,14 @@ Variables named `apple` and `APPLE` are two different variables.
 ```
 
 ````smart header="Non-Latin letters are allowed, but not recommended"
-It is possible to use any language, including cyrillic letters, Chinese logograms and so on, like this:
+It is possible to use any language, including Cyrillic letters, Chinese logograms and so on, like this:
 
 ```js
 let имя = '...';
 let 我 = '...';
 ```
 
-Technically, there is no error here. Such names are allowed, but there is an international convention to use English in variable names. Even if we're writing a small script, it may have a long life ahead. People from other countries may need to read it some time.
+Technically, there is no error here. Such names are allowed, but there is an international convention to use English in variable names. Even if we're writing a small script, it may have a long life ahead. People from other countries may need to read it sometime.
 ````
 
 ````warn header="Reserved names"
@@ -260,11 +260,11 @@ const myBirthday = '18.04.1982';
 myBirthday = '01.01.2001'; // error, can't reassign the constant!
 ```
 
-When a programmer is sure that a variable will never change, they can declare it with `const` to guarantee and clearly communicate that fact to everyone.
+When a programmer is sure that a variable will never change, they can declare it with `const` to guarantee and communicate that fact to everyone.
 
 ### Uppercase constants
 
-There is a widespread practice to use constants as aliases for difficult-to-remember values that are known prior to execution.
+There is a widespread practice to use constants as aliases for difficult-to-remember values that are known before execution.
 
 Such constants are named using capital letters and underscores.
 
@@ -289,15 +289,15 @@ Benefits:
 
 When should we use capitals for a constant and when should we name it normally? Let's make that clear.
 
-Being a "constant" just means that a variable's value never changes. But there are constants that are known prior to execution (like a hexadecimal value for red) and there are constants that are *calculated* in run-time, during the execution, but do not change after their initial assignment.
+Being a "constant" just means that a variable's value never changes. But some constants are known before execution (like a hexadecimal value for red) and some constants are *calculated* in run-time, during the execution, but do not change after their initial assignment.
 
 For instance:
 
 ```js
 const pageLoadTime = /* time taken by a webpage to load */;
 ```
 
-The value of `pageLoadTime` is not known prior to the page load, so it's named normally. But it's still a constant because it doesn't change after assignment.
+The value of `pageLoadTime` is not known before the page load, so it's named normally. But it's still a constant because it doesn't change after the assignment.
 
 In other words, capital-named constants are only used as aliases for "hard-coded" values.
 
@@ -307,18 +307,18 @@ Talking about variables, there's one more extremely important thing.
 
 A variable name should have a clean, obvious meaning, describing the data that it stores.
 
-Variable naming is one of the most important and complex skills in programming. A quick glance at variable names can reveal which code was written by a beginner versus an experienced developer.
+Variable naming is one of the most important and complex skills in programming. A glance at variable names can reveal which code was written by a beginner versus an experienced developer.
 
-In a real project, most of the time is spent modifying and extending an existing code base rather than writing something completely separate from scratch. When we return to some code after doing something else for a while, it's much easier to find information that is well-labeled. Or, in other words, when the variables have good names.
+In a real project, most of the time is spent modifying and extending an existing code base rather than writing something completely separate from scratch. When we return to some code after doing something else for a while, it's much easier to find information that is well-labelled. Or, in other words, when the variables have good names.
 
 Please spend time thinking about the right name for a variable before declaring it. Doing so will repay you handsomely.
 
 Some good-to-follow rules are:
 
 - Use human-readable names like `userName` or `shoppingCart`.
-- Stay away from abbreviations or short names like `a`, `b`, `c`, unless you really know what you're doing.
+- Stay away from abbreviations or short names like `a`, `b`, and `c`, unless you know what you're doing.
 - Make names maximally descriptive and concise. Examples of bad names are `data` and `value`. Such names say nothing. It's only okay to use them if the context of the code makes it exceptionally obvious which data or value the variable is referencing.
-- Agree on terms within your team and in your own mind. If a site visitor is called a "user" then we should name related variables `currentUser` or `newUser` instead of `currentVisitor` or `newManInTown`.
+- Agree on terms within your team and in your mind. If a site visitor is called a "user" then we should name related variables `currentUser` or `newUser` instead of `currentVisitor` or `newManInTown`.
 
 Sounds simple? Indeed it is, but creating descriptive and concise variable names in practice is not. Go for it.
 

1-js/02-first-steps/05-types/article.md

@@ -94,13 +94,6 @@ const bigInt = 1234567890123456789012345678901234567890n;
 
 As `BigInt` numbers are rarely needed, we don't cover them here, but devoted them a separate chapter <info:bigint>. Read it when you need such big numbers.
 
-
-```smart header="Compatibility issues"
-Right now, `BigInt` is supported in Firefox/Chrome/Edge/Safari, but not in IE.
-```
-
-You can check [*MDN* BigInt compatibility table](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt#Browser_compatibility) to know which versions of a browser are supported.
-
 ## String
 
 A string in JavaScript must be surrounded by quotes.

1-js/02-first-steps/12-nullish-coalescing-operator/article.md

@@ -76,7 +76,7 @@ alert(firstName || lastName || nickName || "Anonymous"); // Supercoder
 */!*
 ```
 
-Historically, the OR `||` operator was there first. It exists since the beginning of JavaScript, so developers were using it for such purposes for a long time.
+Historically, the OR `||` operator was there first. It's been there since the beginning of JavaScript, so developers were using it for such purposes for a long time.
 
 On the other hand, the nullish coalescing operator `??` was added to JavaScript only recently, and the reason for that was that people weren't quite happy with `||`.
 

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

@@ -7,7 +7,7 @@ Teams behind JavaScript engines have their own ideas about what to implement fir
 
 So it's quite common for an engine to implement only part of the standard.
 
-A good page to see the current state of support for language features is <https://kangax.github.io/compat-table/es6/> (it's big, we have a lot to study yet).
+A good page to see the current state of support for language features is <https://compat-table.github.io/compat-table/es6/> (it's big, we have a lot to study yet).
 
 As programmers, we'd like to use most recent features. The more good stuff - the better!
 
@@ -73,7 +73,6 @@ JavaScript is a highly dynamic language. Scripts may add/modify any function, ev
 
 Two interesting polyfill libraries are:
 - [core js](https://github.com/zloirock/core-js) that supports a lot, allows to include only needed features.
-- [polyfill.io](https://polyfill.io/) service that provides a script with polyfills, depending on the features and user's browser.
 
 
 ## Summary
@@ -85,7 +84,7 @@ Just don't forget to use a transpiler (if using modern syntax or operators) and
 For example, later when you're familiar with JavaScript, you can setup a code build system based on [webpack](https://webpack.js.org/) with the [babel-loader](https://github.com/babel/babel-loader) plugin.
 
 Good resources that show the current state of support for various features:
-- <https://kangax.github.io/compat-table/es6/> - for pure JavaScript.
+- <https://compat-table.github.io/compat-table/es6/> - for pure JavaScript.
 - <https://caniuse.com/> - for browser-related functions.
 
 P.S. Google Chrome is usually the most up-to-date with language features, try it if a tutorial demo fails. Most tutorial demos work with any modern browser though.

1-js/04-object-basics/04-object-methods/8-chain-calls/task.md

@@ -4,7 +4,7 @@ importance: 2
 
 # Chaining
 
-There's a `ladder` object that allows to go up and down:
+There's a `ladder` object that allows you to go up and down:
 
 ```js
 let ladder = {
@@ -21,7 +21,7 @@ let ladder = {
 };
 ```
 
-Now, if we need to make several calls in sequence, can do it like this:
+Now, if we need to make several calls in sequence, we can do it like this:
 
 ```js
 ladder.up();
@@ -32,10 +32,10 @@ ladder.down();
 ladder.showStep(); // 0
 ```
 
-Modify the code of `up`, `down` and `showStep` to make the calls chainable, like this:
+Modify the code of `up`, `down`, and `showStep` to make the calls chainable, like this:
 
 ```js
 ladder.up().up().down().showStep().down().showStep(); // shows 1 then 0
 ```
 
-Such approach is widely used across JavaScript libraries.
+Such an approach is widely used across JavaScript libraries.

1-js/04-object-basics/09-object-toprimitive/article.md

@@ -253,7 +253,7 @@ let obj = {
   }
 };
 
-alert(obj + 2); // 22 ("2" + 2), conversion to primitive returned a string => concatenation
+alert(obj + 2); // "22" ("2" + 2), conversion to primitive returned a string => concatenation
 ```
 
 ## Summary