regex pattern to match single dot

Question

Is it possible to write a pattern such that it checks continuous occurrence of a character

should match

"[email protected]","[email protected]"

and it should not match

"[email protected]".

Basically i need this to check if the email address is valid

Any Suggestions?

Answer 1

If the language supports it, you can use negative look-ahead and look-behind:

(?<!\.)\.(?!\.)

This will only match a period not following or preceding a period. See it in action here.

Answer 2

You can invert you regex to match >1 dots - if it doesn't, string is valid:

\.{2,}