Why source code width in some IDEs is still 80?

Question

When I code in IDEs, I usually use auto-formatter. (e.g. Ctrl+Shift+F in Eclipse)
When the formatter breaks a really long line into multiple lines, it assumes that the screen width is 80 characters long. Why?!
Second question: I can change the default width. but to what?? Is there any optimal length for different languages?

Answer 1

http://katafrakt.me/2017/09/16/80-characters-line-length-limit/
😉😀😉

Answer 2

Nikolay Nachev : it was great! thanQ😊

Answer 3

I set it to 120 for Java. It doesn't look bad. Not really narrow and not too wide.

Answer 4

David Gablinger Why are tabs evil? I've heard people moan about my using tabs before. Is there a tab-hater conspiracy?

Answer 5

as an add-on to Nikolay's comment:
As the link mentions, the 80 characters originating in punchcards, and I believe there are some mathematical libraries like LAPACK for linear algebra that are still in widespread use and are written in FORTRAN 77 (as opposed to FORTRAN 95/03/08), therefore those libraries are bound by the 80 character limit. Also, Tabs are evil :-)
I've heard that some banks still use COBOL systems, which probably have similar limitations.

Answer 6

It comes from times when people were using typewriters - "standard page"... 😀

Answer 7

uhh what web framework is best to use for python web development pls? help

Answer 8

Well, I said it in jest... that said, I believe that the tab was not part of some older official FORTRAN character set and therefore sometimes gave me weird compilation errors (maybe there are further reasons, but that's mine)... IMO I'm both ok with and without tabs, as long as there is a proper guideline for the project

Answer 9

int