JavaScript lazy shortcuts
A cheatsheet by @rstacruz|Refreshed 7 months ago.Refresh|View source on Github

Examples

Examples

n = +'4096'    // n === 4096
s = '' + 200   // s === '200'
now = +new Date()
isPublished = !!post.publishedAt

Shortcuts

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))

.includes is ES6-only, otherwise use .indexOf(val) !== -1 if you don’t polyfill.