sync with main

Author: bogdanbacosca

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

@@ -64,6 +64,7 @@ let message = 'Hello';
 ```
 
 Some people also define multiple variables in this multiline style:
+
 ```js no-beautify
 let user = 'John',
   age = 25,
@@ -103,6 +104,7 @@ For instance, the variable `message` can be imagined as a box labeled `"message"
 We can put any value in the box.
 
 We can also change it as many times as we want:
+
 ```js run
 let message;
 
@@ -149,11 +151,11 @@ So, we should declare a variable once and then refer to it without `let`.
 ````
 
 ```smart header="Functional languages"
-It's interesting to note that there exist [functional](https://en.wikipedia.org/wiki/Functional_programming) programming languages, like [Scala](http://www.scala-lang.org/) or [Erlang](http://www.erlang.org/) that forbid changing variable values.
+It's interesting to note that there exist so-called [pure functional](https://en.wikipedia.org/wiki/Purely_functional_programming) programming languages, such as [Haskell](https://en.wikipedia.org/wiki/Haskell), that forbid changing variable values.
 
 In such languages, once the value is stored "in the box", it's there forever. If we need to store something else, the language forces us to create a new box (declare a new variable). We can't reuse the old one.
 
-Though it may seem a little odd at first sight, these languages are quite capable of serious development. More than that, there are areas like parallel computations where this limitation confers certain benefits. Studying such a language (even if you're not planning to use it soon) is recommended to broaden the mind.
+Though it may seem a little odd at first sight, these languages are quite capable of serious development. More than that, there are areas like parallel computations where this limitation confers certain benefits.
 ```
 
 ## Variable naming [#variable-naming]
@@ -192,11 +194,11 @@ let my-name; // hyphens '-' aren't allowed in the name
 ```
 
 ```smart header="Case matters"
-Variables named `apple` and `AppLE` are two different variables.
+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 or even hieroglyphs, like this:
+It is possible to use any language, including cyrillic letters, Chinese logograms and so on, like this:
 
 ```js
 let имя = '...';
@@ -260,7 +262,6 @@ 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.
 
-
 ### Uppercase constants
 
 There is a widespread practice to use constants as aliases for difficult-to-remember values that are known prior to execution.
@@ -291,13 +292,14 @@ When should we use capitals for a constant and when should we name it normally?
 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.
 
 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.
 
-In other words, capital-named constants are only used as aliases for "hard-coded" values.  
+In other words, capital-named constants are only used as aliases for "hard-coded" values.
 
 ## Name things right