Home » Php » What is a line length “soft limit” and how do I interpret this in the PSR-2 convention?

What is a line length “soft limit” and how do I interpret this in the PSR-2 convention?

Posted by: admin November 30, 2017 Leave a comment

Questions:

I don’t understand this part of php’s PSR-2 convention:

The soft limit on line length MUST be 120 characters; automated style checkers MUST warn but MUST NOT error at the soft limit.

Lines SHOULD NOT be longer than 80 characters; lines longer than that SHOULD be split into multiple subsequent lines of no more than 80 characters each.

I thought “soft limit” meant “try to stick to this limit, but a few characters extra are not a problem”. But then I read the second line and now I don’t get it.

Answers:

It’s pretty easy:

  • 0-80: Always ok
  • 80-120: Acceptable (if there’s a good reason for it, e.g. a string where wrapping it would be ugly)
  • 120+: Lint tools, IDEs, etc. MUST show a warning (but never an error!) since the line might be ugly/unreadable/…
Questions:
Answers:

There is no hard limit in PSR-2.

The MUST (NOT) refers to automated style checkers, not to you as a programmer.

Also note the section that says that no error should be issued when exceeding the soft limit.