add commas

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

@@ -6,7 +6,7 @@ But quite often we find that we need an *ordered collection*, where we have a 1s
 
 It is not convenient to use an object here, because it provides no methods to manage the order of elements. We can’t insert a new property “between” the existing ones. Objects are just not meant for such use.
 
-There exists a special data structure named `Array`, to store ordered collections.
+There exists a special data structure, named `Array`, to store ordered collections.
 
 ## Declaration
 
@@ -136,7 +136,7 @@ A [queue](https://en.wikipedia.org/wiki/Queue_(abstract_data_type)) is one of th
 
 Arrays support both operations.
 
-In practice we need it very often. For example, a queue of messages that need to be shown on-screen.
+In practice, we need it very often. For example, a queue of messages that need to be shown on-screen.
 
 There's another use case for arrays -- the data structure named [stack](https://en.wikipedia.org/wiki/Stack_(abstract_data_type)).
 
@@ -145,7 +145,7 @@ It supports two operations:
 - `push` adds an element to the end.
 - `pop` takes an element from the end.
 
-So new elements are added or taken always from the "end".
+So new elements are added or taken, always from the "end".
 
 A stack is usually illustrated as a pack of cards: new cards are added to the top or taken from the top:
 
@@ -153,9 +153,9 @@ A stack is usually illustrated as a pack of cards: new cards are added to the to
 
 For stacks, the latest pushed item is received first, that's also called LIFO (Last-In-First-Out) principle. For queues, we have FIFO (First-In-First-Out).
 
-Arrays in JavaScript can work both as a queue and as a stack. They allow you to add/remove elements both to/from the beginning or the end.
+Arrays in JavaScript can work both as a queue and as a stack. They allow you to add/remove elements, both to/from the beginning or the end.
 
-In computer science the data structure that allows this, is called [deque](https://en.wikipedia.org/wiki/Double-ended_queue).
+In computer science, the data structure that allows this, is called [deque](https://en.wikipedia.org/wiki/Double-ended_queue).
 
 **Methods that work with the end of the array:**
 
@@ -399,7 +399,7 @@ There is one more syntax to create an array:
 let arr = *!*new Array*/!*("Apple", "Pear", "etc");
 ```
 
-It's rarely used, because square brackets `[]` are shorter. Also there's a tricky feature with it.
+It's rarely used, because square brackets `[]` are shorter. Also, there's a tricky feature with it.
 
 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*.