Merge branch 'master' of github.com:javascript-tutorial/en.javascript.info into sync-f4891457

Author: iliakan

1-js/01-getting-started/1-intro/article.md

@@ -26,7 +26,7 @@ Different engines have different "codenames". For example:
 
 - [V8](https://en.wikipedia.org/wiki/V8_(JavaScript_engine)) -- in Chrome and Opera.
 - [SpiderMonkey](https://en.wikipedia.org/wiki/SpiderMonkey) -- in Firefox.
-- ...There are other codenames like "Trident" and "Chakra" for different versions of IE, "ChakraCore" for Microsoft Edge, "Nitro" and "SquirrelFish" for Safari, etc.
+- ...There are other codenames like "Chakra" for IE, "ChakraCore" for Microsoft Edge, "Nitro" and "SquirrelFish" for Safari, etc.
 
 The terms above are good to remember because they are used in developer articles on the internet. We'll use them too. For instance, if "a feature X is supported by V8", then it probably works in Chrome and Opera.
 

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

@@ -81,10 +81,13 @@ 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, but not in Safari/IE.
+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/08-operators/4-fix-prompt/solution.md

@@ -9,8 +9,7 @@ let b = "2"; // prompt("Second number?", 2);
 alert(a + b); // 12
 ```
 
-What we should do is to convert strings to numbers before `+`. For example, using `Number()` or
-prepending them with `+`.
+What we should do is to convert strings to numbers before `+`. For example, using `Number()` or prepending them with `+`.
 
 For example, right before `prompt`:
 

1-js/02-first-steps/08-operators/article.md

@@ -180,7 +180,7 @@ Parentheses override any precedence, so if we're not satisfied with the default
 
 There are many operators in JavaScript. Every operator has a corresponding precedence number. The one with the larger number executes first. If the precedence is the same, the execution order is from left to right.
 
-Here's an extract from the [precedence table](https://developer.mozilla.org/en/JavaScript/Reference/operators/operator_precedence) (you don't need to remember this, but note that unary operators are higher than corresponding binary ones):
+Here's an extract from the [precedence table](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence) (you don't need to remember this, but note that unary operators are higher than corresponding binary ones):
 
 | Precedence | Name | Sign |
 |------------|------|------|

1-js/02-first-steps/09-comparison/1-comparison-questions/solution.md

@@ -14,7 +14,7 @@ Some of the reasons:
 
 1. Obviously, true.
 2. Dictionary comparison, hence false. `"a"` is smaller than `"p"`.
-3. Again, dictionary comparison, first char of `"2"` is greater than the first char of `"1"`.
+3. Again, dictionary comparison, first char `"2"` is greater than the first char `"1"`.
 4. Values `null` and `undefined` equal each other only.
 5. Strict equality is strict. Different types from both sides lead to false.
 6. Similar to `(4)`, `null` only equals `undefined`.

1-js/02-first-steps/09-comparison/article.md

@@ -9,9 +9,9 @@ In JavaScript they are written like this:
 - Equals: `a == b`, please note the double equality sign `==` means the equality test, while a single one `a = b` means an assignment.
 - Not equals. In maths the notation is <code>&ne;</code>, but in JavaScript it's written as <code>a != b</code>.
 
-In this article we'll learn more about different types of comparisons, how JavaScript makes them, including important peculiarities. 
+In this article we'll learn more about different types of comparisons, how JavaScript makes them, including important peculiarities.
 
-At the end you'll find a good recipe to avoid "javascript quirks"-related issues.
+At the end you'll find a good recipe to avoid "JavaScript quirks"-related issues.
 
 ## Boolean is the result
 
@@ -57,7 +57,7 @@ The algorithm to compare two strings is simple:
 4. Repeat until the end of either string.
 5. If both strings end at the same length, then they are equal. Otherwise, the longer string is greater.
 
-In the examples above, the comparison `'Z' > 'A'` gets to a result at the first step while the strings `"Glow"` and `"Glee"` are compared character-by-character:
+In the examples above, the comparison `'Z' > 'A'` gets to a result at the first step while the strings `'Glow'` and `'Glee'` are compared character-by-character:
 
 1. `G` is the same as `G`.
 2. `l` is the same as `l`.

1-js/02-first-steps/11-logical-operators/6-check-if-in-range/task.md

@@ -4,6 +4,6 @@ importance: 3
 
 # Check the range between
 
-Write an "if" condition to check that `age` is between `14` and `90` inclusively.
+Write an `if` condition to check that `age` is between `14` and `90` inclusively.
 
 "Inclusively" means that `age` can reach the edges `14` or `90`.

1-js/02-first-steps/11-logical-operators/7-check-if-out-range/task.md

@@ -4,6 +4,6 @@ importance: 3
 
 # Check the range outside
 
-Write an `if` condition to check that `age` is NOT between 14 and 90 inclusively.
+Write an `if` condition to check that `age` is NOT between `14` and `90` inclusively.
 
 Create two variants: the first one using NOT `!`, the second one -- without it.

1-js/02-first-steps/11-logical-operators/9-check-login/solution.md

@@ -3,19 +3,19 @@
 ```js run demo
 let userName = prompt("Who's there?", '');
 
-if (userName == 'Admin') {
+if (userName === 'Admin') {
 
   let pass = prompt('Password?', '');
 
-  if (pass == 'TheMaster') {
+  if (pass === 'TheMaster') {
     alert( 'Welcome!' );
-  } else if (pass == '' || pass == null) {
+  } else if (pass === '' || pass === null) {
     alert( 'Canceled' );
   } else {
     alert( 'Wrong password' );
   }
 
-} else if (userName == '' || userName == null) {
+} else if (userName === '' || userName === null) {
   alert( 'Canceled' );
 } else {
   alert( "I don't know you" );

1-js/02-first-steps/11-logical-operators/article.md

@@ -84,7 +84,7 @@ The OR `||` operator does the following:
 
 A value is returned in its original form, without the conversion.
 
-In other words, a chain of OR `"||"` returns the first truthy value or the last one if no truthy value is found.
+In other words, a chain of OR `||` returns the first truthy value or the last one if no truthy value is found.
 
 For instance:
 
@@ -101,9 +101,9 @@ This leads to some interesting usage compared to a "pure, classical, boolean-onl
 
 1. **Getting the first truthy value from a list of variables or expressions.**
 
-    For instance, we have `firstName`, `lastName` and `nickName` variables, all optional.
+    For instance, we have `firstName`, `lastName` and `nickName` variables, all optional (i.e. can be undefined or have falsy values).
 
-    Let's use OR `||` to choose the one that has the data and show it (or `anonymous` if nothing set):
+    Let's use OR `||` to choose the one that has the data and show it (or `"Anonymous"` if nothing set):
 
     ```js run
     let firstName = "";
@@ -115,7 +115,7 @@ This leads to some interesting usage compared to a "pure, classical, boolean-onl
     */!*
     ```
 
-    If all variables were falsy, `Anonymous` would show up.
+    If all variables were falsy, `"Anonymous"` would show up.
 
 2. **Short-circuit evaluation.**
 
@@ -223,7 +223,7 @@ The precedence of AND `&&` operator is higher than OR `||`.
 So the code `a && b || c && d` is essentially the same as if the `&&` expressions were in parentheses: `(a && b) || (c && d)`.
 ````
 
-````warn header="Don't replace `if` with || or &&"
+````warn header="Don't replace `if` with `||` or `&&`"
 Sometimes, people use the AND `&&` operator as a "shorter way to write `if`".
 
 For instance:
@@ -244,7 +244,7 @@ let x = 1;
 if (x > 0) alert( 'Greater than zero!' );
 ```
 
-Although, the variant with `&&` appears shorter, `if` is more obvious and tends to be a little bit more readable. So we recommend using every construct for its purpose: use `if` if we want if and use `&&` if we want AND.
+Although, the variant with `&&` appears shorter, `if` is more obvious and tends to be a little bit more readable. So we recommend using every construct for its purpose: use `if` if we want `if` and use `&&` if we want AND.
 ````