Regular expression string does not contain 2 points in a row

Question

I would like to know if this regular expression is correct to verify that the line does not start with a point, does not end with a point and contains at least one point anywhere, but not the beginning or end:

My problem is that I cannot figure out how to check if there are 2 dots in a row.

/ ^ ([^.]) + ([.]) +. * ([^.]) $ /

Answer 1

It seems you need to use

^[^.]+(?:\.[^.]+)+$

Watch the regex demo

More details

• ^ - beginning of line
• [^.]+- 1 + characters other than .(so the first char cannot be .)
• (?:\.[^.]+)+ - 1 or more (thus, the point inside the line must appear at least once):
  • \. - dot
  • [^.]+ - 1 + , . ( + char, ., , , 2 )
• $ - .

Answer 2

, :

^[^.]+(?:\.[^.]+){2,}$

, .

:

^[^.]+(?:\.[^.]+)+$

:

^[^.]+(?:\.[^.]+){1,2}$