34 lines
795 B
Markdown
34 lines
795 B
Markdown
---
|
|
title: JavaScript lazy shortcuts
|
|
category: JavaScript
|
|
---
|
|
|
|
## Shortcuts
|
|
{: .-left-reference}
|
|
|
|
### Examples
|
|
|
|
```js
|
|
n = +'4096' // n === 4096
|
|
s = '' + 200 // s === '200'
|
|
```
|
|
|
|
```js
|
|
now = +new Date()
|
|
isPublished = !!post.publishedAt
|
|
```
|
|
|
|
### Shortcuts
|
|
|
|
| What | Lazy mode | "The right way" |
|
|
| --- | --- | --- |
|
|
| String to number | `+str` | `parseInt(str, 10)` _or_ `parseFloat()` |
|
|
| Math floor | `num | 0` | `Math.floor(num)` |
|
|
| Number to string | `'' + num` | `num.toString()` |
|
|
| Date to UNIX timestamp | `+new Date()` | `new Date().getTime()` |
|
|
| Any to boolean | `!!value` | `Boolean(value)` |
|
|
| Check array contents | `if (~arr.indexOf(v))` | `if (arr.includes(v))` |
|
|
{: .-left-align.-headers}
|
|
|
|
`.includes` is ES6-only, otherwise use `.indexOf(val) !== -1` if you don't polyfill.
|