why dot inside square brackets doesn't match any character?

Question

Why this [.]+ Java regular expression doesn\'t match my \"foo\" text, while .+ matches perfectly (tested here)?

Answer 1

[.] is equivalent to escaping the . (dot) character, i.e. \\..

Once the character appears in a character class, it loses its status as a special character.

As foo doesn't contain any dots, nothing is matched. .+, on the other hand, is a wildcard greedy expression that matches everything.