Regular expression to match standard 10 digit phone number
I want to write a regular expression for a standard US type phone number that supports the following formats:
###-###-####
(###) ###-####
### ### ####
###.###.####
where # means any number. So far I came up with the following expressions
^[1-9]\d{2}-\d{3}-\d{4}
^\(\d{3}\)\s\d{3}-\d{4}
^[1-9]\d{2}\s\d{3}\s\d{4}
^[1-9]\d{2}\.\d{3}\.\d{4}
respectively. I am not quite sure if the last one is correct for the dotted check. I also want to know if there is any way I could write a single expression instead of the 4 different ones that cater to the different formats I mentioned. If so, I am not sure how do I do that. And also how do I modify the expression/expressions so that I can also include a condition to support the area code as optional component. Something like
+1 ### ### ####
where +1 is the area code and it is optional.
Answer
^(\+\d{1,2}\s)?\(?\d{3}\)?[\s.-]\d{3}[\s.-]\d{4}$
Matches the following
123-456-7890
(123) 456-7890
123 456 7890
123.456.7890
+91 (123) 456-7890
If you do not want a match on non-US numbers use
^(\+0?1\s)?\(?\d{3}\)?[\s.-]\d{3}[\s.-]\d{4}$
Update :
As noticed by user Simon Weaver below, if you are also interested in matching on unformatted numbers just make the separator character class optional as [\s.-]?
^(\+\d{1,2}\s)?\(?\d{3}\)?[\s.-]?\d{3}[\s.-]?\d{4}$