Write a regular expression to match phone numbers

Question

I have to write a regular expression to match phone numbers. A phone number can be in any one of the following forms:

(123) 456-7890
(123)456-7890
1234567890
123 456 7890
123-456-7890
123.456.7890

I have to store the regular expression in a variable called re5.

The test cases I have to pass are here: link

I just need the re5 = "..." part, where I need the correct code for the ... part.

This is what I have so far..

re5 = "^(\\d{3}|\\(\\d{3}\\))([ ]?\\d{3}[-]|[ ]\\".

I don't know what is going wrong. Thanks!

Different that other answers due to test cases in link above.

Try [`^(?:$\d{3}$ ?\d{3}-|\d{6}|\d{3}([ .-])\d{3}\1)\d{4}$`](https://regex101.com/r/zZ7cIV/3) — ctwheels, Mar 14 '18 at 15:15
Can you just get all the numbers from each string? `library(stringr); paste0(str_extract_all(phone_string, regex("[0-9]"), T), collapse = '')` — IceCreamToucan, Mar 14 '18 at 15:20
(\d{3})\W{0,2}(\d{3})\W{0,1}(\d{4}) You can try this too. Seems short. You can look at the demo [here](https://regex101.com/r/l1tdot/1) — Onyambu, Mar 14 '18 at 15:51

score 0 · Answer 1 · answered Mar 14 '18 at 15:40

0

This passes all your tests:

^(?:\(\d{3}\)|\d{3})(?: |([-.])?)\d{3}(?(1)\1|[ -.]?)\d{4}$

Bear in mind that this uses PCRE-specific syntax, so you'll need to enable that using perl = TRUE

answered Mar 14 '18 at 15:40

squirl

1 Answers1