Don't use that in prod, because it doesn't work in IE and it will cause your js to stop working.

In IE the 'console' object doesn't even exist if the developer tools aren't displayed, so if you use "console.log" in your program, your js will just throw an NPE.

Note that if you try closing the Developer Tools, 'console' is still declared for this page and all descendant pages. To test 'console.log' you need to avoid opening the devtools and open a new tabs.

I don't remember when exactly, but they fixed that at some point. I just ran this simple test in IE (without ever opening the dev tools) and got the alert: http://jsbin.com/hodavocuwu/1/edit

The simple solution is to polyfill: https://github.com/paulmillr/console-polyfill

Another solution is to remove all debug commands as part of your build/deploy process.

too right, extremely annoying bug, because when you open the dev tools to debug it, it starts working again!

that hasn't been the case since IE 9

This person is reporting it for IE10, do you have more insights? Do you think his IE was in compatibility mode? http://stackoverflow.com/questions/18480948/ie-10-debug-cons...

yep. compat mode.

> Don't use that in prod

A linter will catch this.

Indeed, all of these are in Firefox, in Nightly at least. Though console.profile and console.profileEnd didn't seem to work? I'm sure someone from FF dev tools will turn up in this thread to clarify.

time/timeEnd, profile/profileEnd all work in Firefox up to Aurora -- current nightly has a new performance tool that will support profile/profileEnd in a few days, and will most definitely have it before uplift to Aurora https://bugzil.la/1077464