Phone number regexp

[chili5]

I'm trying to come up with a regexp that can be used to validate Canadian and United States phone number. Now in Canada, it is required to use a 3 digit area code, then the actual phone number. From what I know it's not required in the United States to do that.

Well I came up with:

PHP Code:

if (preg_match("/[0-9]{3}?-[0-9]{3}-[0-9]{4}/", "555-5555")) {
    echo "Valid phone number.";
} 


that matches any 3 digit code, then another 3 digit code, then any 4 digit codes. Such as 555-555-5555 but if the phone number being validated doesn't use an area code then it will fail because it doesn't match. If the user provides

555-5555 it will match the first part [0-9]{3}? but then will fail the next part of the regexp. Any ideas to correct this?

[MeTh0Dz|Reb0rn]

If it fails then have it check for the number without the area code. Then if that fails you can assume that it is an invalid number.

[chili5]

I could do that, but I didn't think of this before, just check the phone number against two regular expressions (one with the area code, and one without it) like so:

PHP Code:

if (preg_match("/[0-9]{3}?-[0-9]{3}-[0-9]{4}/", "555-555-5555") || preg_match("/[0-9]{3}?-[0-9]{4}/","555-5555")) {
    echo "Valid phone number.<br />";
} else {
    echo "Invalid phone number.<br />";
} 


I think that is more simple, and it still does work.

[MeTh0Dz|Reb0rn]

Yeah that's fine.

[John]

How about this?

"/([0-9]{3}-?){1,2}[0-9]{4}/"

[chili5]

Thanks, I think that would work because the area code is supposed to be in (). Thanks a bunch.

[chili5]

Thanks I guess I have a lot of reviewing on this to do.

[John]

This:

([0-9]{3}-?)

simply groups "three digits and a dash" together. The {1,2} quantifier, says that the "three digits and a dash can occur once or twice."

Using your regular expression this may work

/[0-9]{3}-[0-9]{3}?-[0-9]{4}/

but I like mine better

[chili5]

I'll go with yours, because I think it works really well, with a lot of different formats. You know any good sites to learn how to use these better? I think they are really hard to learn and a reference of all the characters used would be great.

[John]

I'm in the process of writing a tutorial. You can expect it in a few days.