topic Re: how to find repeated pattern in phone number in SAS Programming

how to find repeated pattern in phone number

gyambqt — Tue, 06 Mar 2018 07:03:52 GMT

Hi Experts,

I have a list of phone number that including both Australia and oversea. the length of the phone number is undefined (can be anything)

I want to know if there is a smart way to find repeated pattern within any phone number without using regular expression.

for example: 04123123123 has repeated pattern 123123123

or 1212121212

has repeated pattern 1212121212

thanks

Re: how to find repeated pattern in phone number

Patrick — Tue, 06 Mar 2018 08:49:52 GMT

And why don't you want to use RegEx as that's the "ideal" syntax for anything pattern?

Re: how to find repeated pattern in phone number

Astounding — Tue, 06 Mar 2018 08:51:15 GMT

Do the repetitions have to be consecutive, or could this be a repeating pattern: 1234123

Could a repeating pattern contain as few as four digits (the original two, plus one repetition)?

Re: how to find repeated pattern in phone number

gyambqt — Tue, 06 Mar 2018 10:50:05 GMT

Yes it can has repeats like that . But I want to remove the one that obviously invalid phone number.

Re: how to find repeated pattern in phone number

gyambqt — Tue, 06 Mar 2018 10:51:07 GMT

Hi Patrick, I thought there might be some mathematic tricks like 12121212 is divisible by 10101 that able to solve the issue.

Re: how to find repeated pattern in phone number

Astounding — Tue, 06 Mar 2018 14:59:25 GMT

Well, it's not really clear what "obvious" means in this context. So here's an example of how to do this for three-digit sets of digits:

length repeated3 $ 3;

if length(phoneno) >= 6 then do k=1 to length(phoneno)-5;

repeated3 = substr(phoneno, k);

if index( substr(phoneno, k+3), repeated3) then output;

end;

Re: how to find repeated pattern in phone number

Patrick — Tue, 06 Mar 2018 20:22:01 GMT

@gyambqt wrote:
Hi Patrick, I thought there might be some mathematic tricks like 12121212 is divisible by 10101 that able to solve the issue.

May be. But especially because this is about the very common case of phone number validation I'd go for RegEx. There should be a lot of RegEx published on the Internet and you won't have to "invent" everything from scratch. Just search a bit and use the one closest to your needs as a starting point.