Question

To make it clear, this is just part of what my Input string can be, therefor its important the regex work as a bool, since I only wanna change the input if it looks like v1 & v2.

Got a string input that can be writtin like this.

(Just an example, it’s not ip adresses I’m working with)

string v1 => "192.168.0.1"

string v2 => "192 168 0 1"

string v3 => "19216801"

I have to rewrite the first 2 versions into version 3

Im thinking something like this.

version 1 
If input is of lenght X and only contains numbers and dots 
Then Replace(".", "").

version 2 
If input is of lenght x and only contains numbers and whitespaces 
Then Replace(" ", "").

How would it look in a more precise regex?

    3 numbers and (1 dot or whitespace) 
and 3 numbers and (1 dot or whitespace) 
and 1 number and (1 dot or whitespace) 
and 1 number

Answer 1

Try this expression

^(\d{3})[. ](\d{3})[. ](\d)[. ](\d)$

and replace with

$1$2$3$4

See it here on Regexr

^ anchors on the start of the string

$ anchors on the end of the string

\d{3} matches 3 digits (accordingly \d matches one digit)

[. ] is a character class matching either a dot or a space.