Why use angular's $log instead of console.log?

Question

I understand it is a best practice in angular to use $log instead of console.log. However, I can't find good documentation explaining the reasons. Why should a developer use $log?

Answer 1

$log first checks if the browser supports console.log (IE 8, for example, doesn't). This prevents errors being displayed on IE 8. Note: this doesn't mean it will log anything on IE 8, it simply means it won't throw the error.

Next to that, it also allows you to decorate and mock $log for extending and testing purposes, if you are so inclined. You could for example decorate it to log to an array for IE 8 support.

A bonus feature: if you pass it a JavaScript Error instance, it will attempt to format it nicely. This can be found out by reading the source code.

EDIT: "It is not that IE 8 doesn't support console.log. It just doesn't create the console object until the dev tools are opened." See comments below for more details.

Answer 2

Just to complete @Steve's answer (which is correct), $log also has the advantage of being turned off. Using this code you can disable the logging from $log:

app.config(function($logProvider) {   $logProvider.debugEnabled(true); }); 

This is very handy if you want to disable all logs at once, rather than delete them line by line manually.