If you’ve ever opened up your browser tools while logged into Facebook you might have noticed the above in it (at least, this is what it looks like at the time of writing). DOM warning aside, it looks a bit different to most console.log messages you’re probably generating, doesn’t it? A big bit of red text and some other slightly larger text. That’s a bit weird, isn’t it? As it turns out the console functions have a number of formatting options, so if you want to display numbers to certain decimal places you can use %.