Js_lazy-cheatsheets速查表
Shortcuts
{: .-left-reference}
Examples
n = +'4096' // n === 4096
s = '' + 200 // s === '200'now = +new Date()
isPublished = !!post.publishedAtShortcuts
| 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.