Merge pull request #1 from javascript-tutorial/master

Update master

1-js/01-getting-started/4-devtools/article.md

@@ -29,10 +29,15 @@ The exact look of developer tools depends on your version of Chrome. It changes
 - Here we can see the red-colored error message. In this case, the script contains an unknown "lalala" command.
 - On the right, there is a clickable link to the source `bug.html:12` with the line number where the error has occurred.
 
-Below the error message, there is a blue `>` symbol. It marks a "command line" where we can type JavaScript commands. Press `key:Enter` to run them (`key:Shift+Enter` to input multi-line commands).
+Below the error message, there is a blue `>` symbol. It marks a "command line" where we can type JavaScript commands. Press `key:Enter` to run them.
 
 Now we can see errors, and that's enough for a start. We'll come back to developer tools later and cover debugging more in-depth in the chapter <info:debugging-chrome>.
 
+```smart header="Multi-line input"
+Usually, when we put a line of code into the console, and then press `key:Enter`, it executes.
+
+To insert multiple lines, press `key:Shift+Enter`. This way one can enter long fragments of JavaScript code.
+```
 
 ## Firefox, Edge, and others
 
@@ -50,12 +55,6 @@ Open Preferences and go to the "Advanced" pane. There's a checkbox at the bottom
 
 Now `key:Cmd+Opt+C` can toggle the console. Also, note that the new top menu item named "Develop" has appeared. It has many commands and options.
 
-```smart header="Multi-line input"
-Usually, when we put a line of code into the console, and then press `key:Enter`, it executes.
-
-To insert multiple lines, press `key:Shift+Enter`. This way one can enter long fragments of JavaScript code.
-```
-
 ## Summary
 
 - Developer tools allow us to see errors, run commands, examine variables, and much more.

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

@@ -10,7 +10,7 @@ message = 123456;
 
 Programming languages that allow such things are called "dynamically typed", meaning that there are data types, but variables are not bound to any of them.
 
-There are seven basic data types in JavaScript. Here, we'll cover them in general and in the next chapters we'll talk about each of them in detail.
+There are eight basic data types in JavaScript. Here, we'll cover them in general and in the next chapters we'll talk about each of them in detail.
 
 ## A number
 
@@ -180,6 +180,31 @@ All other types are called "primitive" because their values can contain only a s
 
 The `symbol` type is used to create unique identifiers for objects. We mention it here for completeness, but we'll study it after objects.
 
+## BigInt
+
+In JavaScript, the Number type cannot represent integer values larger than 2<sup>53</sup>-1. This limitation has forced many of us to use inefficient workarounds. BigInt is a new data type intended to fix just that. A BigInt is created by appending n to the end of an integer literal — 10n — or by calling the function BigInt().
+
+```js run
+const theBiggestInt = 9007199254740991n;
+
+const huge = BigInt(9007199254740991);
+
+alert(typeof biggestInt); // shows "bigint"
+
+alert(typeof huge); // shows "bigint"
+```
+Bigint can mostly be used like number but there are some key differences
+- Most math operatioons work on it normally
+- It cannot be mixed and match with number while apllying binary operations it has to be coerced into each other but be careful it can lead to some precision losses
+- The / operator also works as expected with whole numbers. However, since these are BigInts and not BigDecimals, this operation will round towards 0, which is to say, it will not return any fractional digits.
+
+To  know more in detail about the java script newest addition in prmitive types please visit [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt) docs for it
+
+
+```smart header="Compatability issues"
+Right now it only compatible with firefox and chrome but is not supported in Safari.
+```
+
 ## The typeof operator [#type-typeof]
 
 The `typeof` operator returns the type of the argument. It's useful when we want to process values of different types differently or just want to do a quick check.
@@ -226,7 +251,7 @@ The last three lines may need additional explanation:
 
 ## Summary
 
-There are 7 basic data types in JavaScript.
+There are 8 basic data types in JavaScript.
 
 - `number` for numbers of any kind: integer or floating-point.
 - `string` for strings. A string may have one or more characters, there's no separate single-character type.
@@ -235,6 +260,7 @@ There are 7 basic data types in JavaScript.
 - `undefined` for unassigned values -- a standalone type that has a single value `undefined`.
 - `object` for more complex data structures.
 - `symbol` for unique identifiers.
+- `bigint` is for displaying numbers greater than 2<sup>53</sup>-1
 
 The `typeof` operator allows us to see which type is stored in a variable.
 

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 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 systems like [webpack](http://webpack.github.io/) provide means to run transpiler automatically on every code change, so that very easy to integrate into development process.
+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 systems like [webpack](http://webpack.github.io/) provide means to run transpiler automatically on every code change, so that it's very easy to integrate into development process.
 
 2. Second, the polyfill.