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grammar, usage, punctuation edits, Part 1, sections 2.9 - 2.16

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Jeff Bothe 2017-08-09 19:01:02 -05:00
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1-js/02-first-steps/10-ifelse/article.md
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@ -2,13 +2,13 @@
Sometimes we need to perform different actions based on a condition.
There is `if` statement for that and also the conditional (ternary) operator for conditional evaluation which we will be referring as “question mark” operator: `"?"` for simplicity.
There is the `if` statement for that and also the conditional (ternary) operator for conditional evaluation which we will be referring as the “question mark” operator: `"?"` for simplicity.
[cut]
## The "if" statement
The "if" statement gets a condition, evaluates it and -- if the result is `true` -- executes the code.
The "if" statement gets a condition, evaluates it and, if the result is `true`, executes the code.
For example:
@ -22,7 +22,7 @@ if (year == 2015) alert( 'You are right!' );
In the example above, the condition is a simple equality check: `year == 2015`, but it can be much more complex.
If there is more than one command to execute -- we can use a code block in figure brackets:
If there is more than one command to execute, we can use a code block in figure brackets:
```js
if (year == 2015) {
@ -101,7 +101,7 @@ if (year < 2015) {
}
```
In the code above JavaScript first checks `year < 2015`, if it is falsy then goes to the next condition `year > 2015`, and otherwise shows the last `alert`.
In the code above JavaScript first checks `year < 2015`. If it is falsy it then goes to the next condition `year > 2015`, and otherwise shows the last `alert`.
There can be more `else if` blocks. The ending `else` is optional.
@ -128,7 +128,7 @@ alert(accessAllowed);
The so-called "ternary" or "question mark" operator lets us do that shorter and simpler.
The operator is represented by a question mark `"?"`. The formal term "ternary" means that the operator has 3 operands. It is actually the one and only operator in JavaScript which has that many.
The operator is represented by a question mark `"?"`. The formal term "ternary" means that the operator has three operands. It is actually the one and only operator in JavaScript which has that many.
The syntax is:
```js
@ -151,7 +151,7 @@ Technically, we can omit parentheses around `age > 18`. The question mark operat
let accessAllowed = age > 18 ? true : false;
```
...But parentheses make the code more readable. So it's recommended to put them.
...But parentheses make the code more readable. So it's recommended to use them.
````smart
In the example above it's possible to evade the question mark operator, because the comparison by itself returns `true/false`:
@ -214,13 +214,13 @@ let company = prompt('Which company created JavaScript?', '');
Depending on the condition `company == 'Netscape'`, either the first or the second part after `"?"` gets executed and shows the alert.
We don't assign a result to a variable here, the idea is to execute different code depending on the condition.
We don't assign a result to a variable here. The idea is to execute different code depending on the condition.
**It is not recommended to use the question mark operator in this way.**
The notation seem to be shorter than `if`, that appeals to some programmers. But it is less readable.
The notation seems to be shorter than `if`, which appeals to some programmers. But it is less readable.
Here is the same with `if` for comparison:
Here is the same code with `if` for comparison:
```js run no-beautify
let company = prompt('Which company created JavaScript?', '');