alert messages anymore, or using a DOM element to display them.
But, what I didn't know back then was that there are different ways to display messages in the console, apart from the well-known
I'm going to present the different types of messages that we can use in each major browser, focusing on their visual differences:
In most of the browsers, there are five different methods for styling messages:
log() method is the default in all of them, having the simplest style.
The screenshots are the outcome of the following script that I run into every browser (well, apart from IE, but we'll get there):
console.log('console.log'); console.info('console.info'); console.debug('console.debug'); console.warn('console.warn'); console.error('console.error');
In Chrome, the
info() method is the same as
debug() method displays the messages with a blue colour; the
warn() method adds a warning sign in front of the message; and the
error() method both adds an error sign in front of the message, and changes the text colour to red (also includes a stack trace from where the method was called, but now we're moving away for the visual discussion).
Here's a screenshot of the script's outcome in Chrome 29:
Before moving to the next browser, Chrome also allows us to style each of the above methods' text outcome overriding the default styling, using the
%c format specifier, as follows:
console.log('%cThis text will now be blue and large', 'color: blue; font-size: x-large');
Moving on, in Opera,
debug() methods are the same,
info() method's text is blue,
warn() method's text is orange-yellow-ish (or something like that), and
error() method's text is red. There are no icons.
Here's a screenshot of the script's outcome in Opera 12:
In Firefox, all of them (note that although it's working, the
debug() method is deprecated) have the same text colour, but
error() methods have their own individual icons.
Here's a screenshot of the script's outcome in Firefox 21:
If you are using Internet Explorer 10, don't use the
debug() method, since it will crash your script. The rest of them have different colours and icons.
Here's a screenshot of the script's outcome (without
debug()) in Internet Explorer 10:
Finally, in Safari, all apart from the
error() method have the same (black) colour, and only
error() methods include icons.
Here's a screenshot of the script's outcome in Safari 5:
Console has more power than just custom messages though. I would strongly recommend reading your preferred browser's documentation about its console API, to discover more.
Here is a list of links to each browser's documentation: