Regular expression, How to allow combination of dot (period) and letters?

Question

I want to allow (.) and (a-zA-Z) letters and _ and - , I have some problems with the (.) ,

Any idea ?

Thanks in advance ,

Ish

Answer 1

[A-Za-z_.-]

is a character class that includes all the characters you mentioned. Inside a character class, it's not necessary to escape the ., and you can avoid escaping the - if you put it first or last.

If numbers are ok, too, you can shorten this to

[\w.-]

Answer 2

This will do [a-zA-Z_.-]+

Outside the character class, ([]), you need to escape the dot (\.)as it is a meta character.

[a-z]+\.com  #matches `something.com`

Answer 3

[a-zA-Z_\-.] should work. You might have to use a double slash, depending on the language you are using.