Default bootstrap for debugging script code - is this necessary?

Question

In some bootstrap template examples, they include the following code:

<!-- Just for debugging purposes. Don't actually copy these 2 lines! --> <!--[if lt IE 9]><script src="../../assets/js/ie8-responsive-file-warning.js"></script><![endif]--> 

Does this mean that these lines should not actually be included in the final assembly of the site? I searched for several development sites where people ask about including bootstrap in their projects, and most of the answers are cut and pasted from bootstrap examples, including these lines. So just try to find out if they should be deleted when creating the actual site.

Thanks.

Answer 1

Does this mean that these lines should not be included in the final assembly of the site?

Yes, you should exclude these lines. Otherwise, I would not add that explanatory HTML comment in the first place .

All ie8-responsive-file-warning.js makes an error message to developers trying to use file:// URL with IE8. This is not useful in production code.

Similarly, ie-emulation-modes-warning.js simply displays an error message to developers trying to improperly use the IE untrusted emulation modes feature. Again, not useful in production.

Answer 2

Lines will warn for users with IE 8 or later. If this is what you want, leave them.