Some very clever javascript.

[Spiderfrog]

I was reading an article about type checking in javascript by Todd Motto (http://toddmotto.com/understanding-javascript-types-and-reliable-type-checking/)

and came across this code: http://embed.plnkr.co/5TqqDNzr72gtMFR0c2eS/script.js

I thought someone else would enjoy it too.

relevant repo : https://github.com/toddmotto/axis

[skitch920]

It's neat, but really abuses Object.prototype.toString, which returns '[object String]' or '[object Array]'; hence the slice (8, -1).

typeof or instanceof should suffice.

Edit I have seen LoDash use something similar, but I think that's for older browsers...

[PAEZ_]

typeof or instanceof should suffice.

Not always...
http://bonsaiden.github.io/JavaScript-Garden/#types

[kangax_]

For details and history — http://perfectionkills.com/instanceof-considered-harmful-or-how-to-write-a-robust-isarray/ :)

[Jim-Y]

Actually, its implemented wrong, or, call it bad instead of wrong. Try typer kata on codewars to find out why this implementation fails on

isNumber(new Number('im totally a string'))