minor fixes

1-js/06-advanced-functions/04-var/article.md

@@ -31,7 +31,7 @@ alert(phrase); // Error, phrase is not defined
 
 ## "var" has no block scope
 
-`var` variables are either function-wide or global, they are visible through blocks.
+Variables, declared with `var`, are either function-wide or global. They are visible through blocks.
 
 For instance:
 
@@ -45,7 +45,7 @@ alert(test); // true, the variable lives after if
 */!*
 ```
 
-`var` ignores code blocks, so we've got a global variable `test`.
+As `var` ignores code blocks, we've got a global variable `test`.
 
 If we used `let test` instead of `var test`, then the variable would only be visible inside `if`:
 

1-js/06-advanced-functions/08-settimeout-setinterval/article.md

@@ -9,7 +9,6 @@ There are two methods for it:
 
 These methods are not a part of JavaScript specification. But most environments have the internal scheduler and provide these methods. In particular, they are supported in all browsers and Node.js.
 
-
 ## setTimeout
 
 The syntax:
@@ -291,9 +290,9 @@ For server-side JavaScript, that limitation does not exist, and there exist othe
 - To cancel the execution, we should call `clearInterval/clearTimeout` with the value returned by `setInterval/setTimeout`.
 - Nested `setTimeout` calls is a more flexible alternative to `setInterval`. Also they can guarantee the minimal time *between* the executions.
 - Zero delay scheduling with `setTimeout(func, 0)` (the same as `setTimeout(func)`) is used to schedule the call "as soon as possible, but after the current code is complete".
-- The browsere ensures that for five or more nested call of `setTimeout`, or for zero-delay `setInterval`, the real delay between calls is at least 4ms. That's for historical reasons.
+- The browser limits the minimal delay for five or more nested call of `setTimeout` or for `setInterval` (after 5th call) to 4ms. That's for historical reasons.
 
-Please note that all scheduling methods do not *guarantee* the exact delay. We should not rely on that in the scheduled code.
+Please note that all scheduling methods do not *guarantee* the exact delay. 
 
 For example, the in-browser timer may slow down for a lot of reasons:
 - The CPU is overloaded.

1-js/07-object-properties/01-property-descriptors/article.md

@@ -122,7 +122,7 @@ user.name = "Pete"; // Error: Cannot assign to read only property 'name'...
 
 Now no one can change the name of our user, unless they apply their own `defineProperty` to override ours.
 
-```smart header="Errors appear only in use strict"
+```smart header="Errors appear only in strict mode"
 In the non-strict mode, no errors occur when writing to read-only properties and such. But the operation still won't succeed. Flag-violating actions are just silently ignored in non-strict.
 ```
 

1-js/11-async/05-promise-api/article.md

@@ -112,7 +112,7 @@ Promise.all(requests)
   ));
 ```
 
-A bigger example with fetching user information for an array of github users by their names (or we could fetch an array of goods by their ids, the logic is same):
+A bigger example with fetching user information for an array of GitHub users by their names (we could fetch an array of goods by their ids, the logic is same):
 
 ```js run
 let names = ['iliakan', 'remy', 'jeresig'];
@@ -134,7 +134,7 @@ Promise.all(requests)
   .then(users => users.forEach(user => alert(user.name)));
 ```
 
-**If any of the promises is rejected, `Promise.all` immediately rejects with that error.**
+**If any of the promises is rejected, the promise returned by `Promise.all` immediately rejects with that error.**
 
 For instance:
 
@@ -155,10 +155,10 @@ If one promise rejects, `Promise.all` immediately rejects, completely forgetting
 
 For example, if there are multiple `fetch` calls, like in the example above, and one fails, other ones will still continue to execute, but `Promise.all` don't watch them any more. They will probably settle, but the result will be ignored.
 
-`Promise.all` does nothing to cancel them, as there's no concept of "cancellation" in promises. In [another chapter](fetch-abort) we'll cover `AbortController` that aims to help with that, but it's not a part of the Promise API.
+`Promise.all` does nothing to cancel them, as there's no concept of "cancellation" in promises. In [another chapter](info:fetch-abort) we'll cover `AbortController` that can help with that, but it's not a part of the Promise API.
 ```
 
-````smart header="`Promise.all(...)` allows non-promise items in `iterable`"
+````smart header="`Promise.all(iterable)` allows non-promise \"regular\" values in `iterable`"
 Normally, `Promise.all(...)` accepts an iterable (in most cases an array) of promises. But if any of those objects is not a promise, it's wrapped in `Promise.resolve`.
 
 For instance, here the results are `[1, 2, 3]`:
@@ -173,8 +173,7 @@ Promise.all([
 ]).then(alert); // 1, 2, 3
 ```
 
-So we are able to pass non-promise values to `Promise.all` where convenient.
-
+So we are able to pass ready values to `Promise.all` where convenient.
 ````
 
 ## Promise.allSettled
@@ -289,4 +288,4 @@ There are 5 static methods of `Promise` class:
     - `value` (if fulfilled) or `reason` (if rejected).
 5. `Promise.race(promises)` -- waits for the first promise to settle, and its result/error becomes the outcome.
 
-Of these five, `Promise.all/allSettled` are the most common in practice.
+Of these five, `Promise.all` is probably the most common in practice.

1-js/11-async/07-microtask-queue/article.md

@@ -21,7 +21,7 @@ That's strange, because the promise is definitely done from the beginning.
 
 Why did the `.then` trigger afterwards? What's going on?
 
-## Microtasks
+## Microtasks queue
 
 Asynchronous tasks need proper management. For that, the standard specifies an internal queue `PromiseJobs`, more often referred to as "microtask queue" (v8 term).
 
@@ -68,7 +68,7 @@ let promise = Promise.reject(new Error("Promise Failed!"));
 promise.catch(err => alert('caught'));
 */!*
 
-// no error, all quiet
+// doesn't run: error handled
 window.addEventListener('unhandledrejection', event => alert(event.reason));
 ```
 
@@ -93,13 +93,13 @@ setTimeout(() => promise.catch(err => alert('caught')), 1000);
 window.addEventListener('unhandledrejection', event => alert(event.reason));
 ```
 
-Now, if you run it, we'll see `Promise Failed!` message first, and then `caught`.
+Now, if you run it, we'll see `Promise Failed!` message first, and then `caught`. 
 
-If we didn't know about microtasks, we could wonder: "Why did `unhandledrejection` happen? We did catch the error!".
+If we didn't know about microtasks queue, we could wonder: "Why did `unhandledrejection` handler run? We did catch the error!".
 
-But now we do know that `unhandledrejection` is generated when the microtask queue is complete: the engine examines promises and, if any of them is in "rejected" state, then the event triggers.
+But now we understand that `unhandledrejection` is generated when the microtask queue is complete: the engine examines promises and, if any of them is in "rejected" state, then the event triggers.
 
-...By the way, the `.catch` added by `setTimeout` also triggers, of course it does, but later, after `unhandledrejection` has already occurred.
+In the example above, `.catch` added by `setTimeout` also triggers, but later, after `unhandledrejection` has already occurred, so that doesn't change anything.
 
 ## Summary
 

2-ui/1-document/09-size-and-scroll/article.md

@@ -39,7 +39,9 @@ So, without scrollbar the content width would be `300px`, but if the scrollbar i
 ```
 
 ```smart header="The `padding-bottom` area may be filled with text"
-Usually paddings are shown empty on illustrations, but if there's a lot of text in the element and it overflows, then browsers show the "overflowing" text at `padding-bottom`, so you can see that in examples. Still, the padding is set in further examples, unless explicitly specified otherwise.
+Usually paddings are shown empty on illustrations, but if there's a lot of text in the element and it overflows, then browsers show the "overflowing" text at `padding-bottom`.
+
+That's a note to avoid confusion, as `padding-bottom` is set in further examples, unless explicitly specified otherwise.
 ```
 
 ## Geometry
@@ -66,7 +68,7 @@ That's the nearest ancestor, that satisfies following conditions:
 2. or `<td>`, `<th>`, `<table>`,
 2. or `<body>`.
 
-In most practical cases `offsetParent` is exactly the nearest ancestor, that is CSS-positioned. And `offsetLeft/offsetTop` provide x/y coordinates relative to its upper-left corner.
+Properties `offsetLeft/offsetTop` provide x/y coordinates relative to its upper-left corner.
 
 In the example below the inner `<div>` has `<main>` as `offsetParent` and `offsetLeft/offsetTop` shifts from its upper-left corner (`180`):
 
@@ -105,7 +107,7 @@ For our sample element:
 - `offsetWidth = 390` -- the outer width, can be calculated as inner CSS-width (`300px`) plus paddings (`2 * 20px`) and borders (`2 * 25px`).
 - `offsetHeight = 290` -- the outer height.
 
-````smart header="Geometry properties for not displayed elements are zero/null"
+````smart header="Geometry properties are zero/null for elements that are not displayed"
 Geometry properties are calculated only for displayed elements.
 
 If an element (or any of its ancestors) has `display:none` or is not in the document, then all geometry properties are zero (or `null` if that's `offsetParent`).