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Merge pull request #34 from reigningmetal/master

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Small spelling changes
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Ilya Kantor 2017-06-12 15:33:49 +03:00 • committed by GitHub
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4
1-js/01-getting-started/1-intro/article.md
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@ -67,12 +67,12 @@ The examples of such restrictions are:
Modern browsers allow it to work with files, but the access is limited and only provided if the user does certain actions, like "dropping" a file into a browser window or selecting it via an `<input>` tag. Modern browsers allow it to work with files, but the access is limited and only provided if the user does certain actions, like "dropping" a file into a browser window or selecting it via an `<input>` tag.
There are ways to interact with camera/microphone and other devices, but they require an explicit user's permission. So a JavaScript-enabled page may not sneakily enable a web-camera, observe the surroundings and send the information to the [NSA](https://en.wikipedia.org/wiki/National_Security_Agency). There are ways to interact with camera/microphone and other devices, but they require a user's explicit permission. So a JavaScript-enabled page may not sneakily enable a web-camera, observe the surroundings and send the information to the [NSA](https://en.wikipedia.org/wiki/National_Security_Agency).
- Different tabs/windows generally do not know about each other. Sometimes they do, for example when one window uses JavaScript to open the other one. But even in this case, JavaScript from one page may not access the other if they come from different sites (from a different domain, protocol or port). - Different tabs/windows generally do not know about each other. Sometimes they do, for example when one window uses JavaScript to open the other one. But even in this case, JavaScript from one page may not access the other if they come from different sites (from a different domain, protocol or port).
That is called a "Same Origin Policy". To workaround that, *both pages* must contain a special JavaScript code that handles data exchange. That is called a "Same Origin Policy". To workaround that, *both pages* must contain a special JavaScript code that handles data exchange.
The limitation is again for user's safety. A page from `http://anysite.com` which a user has opened occasionaly must not be able to open or access another browser tab with the URL `http://gmail.com` and steal information from there. The limitation is again for user's safety. A page from `http://anysite.com` which a user has opened occasionally must not be able to open or access another browser tab with the URL `http://gmail.com` and steal information from there.
- JavaScript can easily communicate over the net to the server where the current page came from. But its ability to receive data from other sites/domains is crippled. Though possible, it requires the explicit agreement (expressed in HTTP headers) from the remote side. Once again, that's safety limitations. - JavaScript can easily communicate over the net to the server where the current page came from. But its ability to receive data from other sites/domains is crippled. Though possible, it requires the explicit agreement (expressed in HTTP headers) from the remote side. Once again, that's safety limitations.
![](limitations.png) ![](limitations.png)

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1-js/01-getting-started/3-devtools/article.md
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@ -29,9 +29,9 @@ It looks somewhat like this:
The exact look of developer tools depends on your version of Chrome. It changes from time to time, but should be similar. The exact look of developer tools depends on your version of Chrome. It changes from time to time, but should be similar.
- Here we can see the red-colored error message. In this case the script contains an unknown "lalala" command. - 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 occured. - 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 and press `key:Enter` to run them (`key:Shift+Enter` to input multiline commands). Below the error message there is a blue `>` symbol. It marks a "command line" where we can type JavaScript commands and press `key:Enter` to run them (`key:Shift+Enter` to input multi-line commands).
Now we can see errors and that's enough for the start. We'll be back to developer tools later and cover debugging more in-depth in the chapter <info:debugging-chrome>. Now we can see errors and that's enough for the start. We'll be back to developer tools later and cover debugging more in-depth in the chapter <info:debugging-chrome>.

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1-js/02-first-steps/04-variables/article.md
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@ -141,7 +141,7 @@ It may be interesting to know that there also exist [functional](https://en.wiki
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 to create a new box (declare a new variable), we can't reuse the old one. 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 to create a new box (declare a new variable), we can't reuse the old one.
Though it may seem a little bit odd at the first sight, these languages are quite capable of serious development. More than that, there are areas like parallel computations where this limitation infers certain benefits. Studying of such a language (even if not planning to use it soon) is recommended to broaden the mind. Though it may seem a little bit odd at first sight, these languages are quite capable of serious development. More than that, there are areas like parallel computations where this limitation infers certain benefits. Studying of such a language (even if not planning to use it soon) is recommended to broaden the mind.
``` ```
## Variable naming [#variable-naming] ## Variable naming [#variable-naming]
@ -277,7 +277,7 @@ Benefits:
When should we use capitals for a constant, and when -- name them normally? Let's make that clear. When should we use capitals for a constant, and when -- name them normally? Let's make that clear.
Being a "constant" just means that the value never changes. But there are constants that are known prior to execution (like a hexadimal value for red), and there are those that are *calculated* in run-time, during the execution, but do not change after the assignment. Being a "constant" just means that the value never changes. But there are constants that are known prior to execution (like a hexadecimal value for red), and there are those that are *calculated* in run-time, during the execution, but do not change after the assignment.
For instance: For instance:
```js ```js
@ -290,7 +290,7 @@ In other words, capital-named constants are only used as aliases for "hard-coded
## Name things right ## Name things right
Talking about variables, there's one more exteremely important thing. Talking about variables, there's one more extremely important thing.
Please name the variables sensibly. Take time to think if needed. Please name the variables sensibly. Take time to think if needed.

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1-js/06-advanced-functions/03-closure/article.md
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@ -15,7 +15,7 @@ Different languages behave differently here, in this chapter we cover JavaScript
## A couple of questions ## A couple of questions
Let's formulate two questions for the seed, and then study internal mechanics piece-by-piece, so that you'll be able to answer these questions and more complex ones in the future. Let's formulate two questions for the seed, and then study the internal mechanics piece-by-piece, so that you'll be able to answer these questions and more complex ones in the future.
1. The function `sayHi` uses an external variable `name`. When the function runs, which value of these two it's going to use? 1. The function `sayHi` uses an external variable `name`. When the function runs, which value of these two it's going to use?
@ -176,7 +176,7 @@ sayHi(); // Pete
The execution flow of the code above: The execution flow of the code above:
1. The global Lexical Envrionment has `name: "John"`. 1. The global Lexical Environment has `name: "John"`.
2. At the line `(*)` the global variable is changed, now it has `name: "Pete"`. 2. At the line `(*)` the global variable is changed, now it has `name: "Pete"`.
3. When the function `say()`, is executed and takes `name` from outside. Here that's from the global Lexical Environment where it's already `"Pete"`. 3. When the function `say()`, is executed and takes `name` from outside. Here that's from the global Lexical Environment where it's already `"Pete"`.
@ -565,7 +565,7 @@ Lexical Environment objects that we've been talking about are subjects to same m
return function() { alert(value); }; return function() { alert(value); };
} }
// 3 functions in array, every of them links to LexicalEnvrironment // 3 functions in array, every of them links to Lexical Environment
// from the corresponding f() run // from the corresponding f() run
// LE LE LE // LE LE LE
let arr = [f(), f(), f()]; let arr = [f(), f(), f()];