Is there a difference between `[^\b]` and `.`?

Question

Is there a difference between [^\b] and .?

I was modifying some code created by someone else that included this no-word-boundary-character-class ([^\b]). and am not able to find a difference between that and wildcard . (this is in ruby).

My assumption was that [^\b]+ when applied to the string hello world should match hello and stop before the space, (as that is where there is a word boundary.

My observation is that it seems to just match everything. rubular link.

What should be happening here?

Any zero-width assertion loses its meaning inside a character class. See [this Ruby demo](https://ideone.com/54MTLn). `[^\b]` matches any char but a backspace char. — Wiktor Stribiżew, Oct 31 '17 at 17:54

score 2 · Accepted Answer · edited Oct 31 '17 at 17:58

2

[\b] means backspace and [^\b] not a backspace

\b is not a character, it can't be included in a character class.

The negation of a word boundary is \B

edited Oct 31 '17 at 17:58

Sergio Tulentsev

210,238
40
347
343

answered Oct 31 '17 at 17:53

Toto

83,193
59
77
109

Backspace? What do you mean? – Sergio Tulentsev Oct 31 '17 at 17:56
1

@SergioTulentsev: The character backspace, octal `010` or decimal `8` – Toto Oct 31 '17 at 17:56
I'll be damned, it does mean that. TIL – Sergio Tulentsev Oct 31 '17 at 17:58

Is there a difference between `[^\b]` and `.`?

1 Answers1