Comments on: Advanced Javascript: Logical Operators and truthy / falsy

By: nFriedly

nFriedly — Thu, 25 Feb 2010 15:58:05 +0000

Because JavaScript is weird…

alert([] == false) // true

alert([] == true) // false

alert( ( [] ) ? ‘truthy’ : ‘falsy’ ) // truthy

I’ll append the original article though, thanks for pointing it out!

Andy Tjin — Thu, 25 Feb 2010 15:25:39 +0000

So you say [] is truthy. But then why is the following true?
[] == false

Chuck Denk — Fri, 12 Jun 2009 19:21:33 +0000

So, && and || in JavaScript act essentially the same as they do in the C programming language, if I’m not mistaken.

nFriedly — Wed, 10 Jun 2009 19:47:41 +0000

Thanks, I just published a new article on objects, arrays & array-like objects that I was writing when your comment came in:

Johan — Wed, 10 Jun 2009 17:52:59 +0000

Great article!

I was always juggeling with if/else and (var ? var : ‘x’) statements.

Thanks alot!

nFriedly — Mon, 08 Jun 2009 14:34:10 +0000

Thanks for pointing the differences between php and javascript. I updated the article to point out how php evaluates empty arrays and “0″ as falsy.

The Truth of JavaScript at Nicollet.Net — Mon, 08 Jun 2009 14:14:07 +0000

[...] nFriedly posted an interesting refresher on JavaScript boolean evaluation of non-boolean values : Logical Operators and Truthy / Falsy. [...]