regular expressions and search() - vertical bar problem

[Ward Cleaver]

Hi. I have an assignment to do some validating of a form using
javascript and mostly the search() method. I'm having problems
getting a positive validation for phone numbers like "123-456-7890"
and "123.456.7890" but not like "123.456-7890". The regular
expression I'm using now is something like this:
ok = pn.search(/(^\d{3}-\d{3}-\d{4}$)|(^\d{3}.\d{3}.\d{4}$)/);
Which to me looks like it SHOULD do what I want it to and not come
back with an ok=0 for a phone number using both hyphens and periods.
Please help.

[RobG]

Ward Cleaver wrote:

ok = pn.search(/(^\d{3}-\d{3}-\d{4}$)|(^\d{3}.\d{3}.\d{4}$)/);

I'm guessing...

(/(^\d{3}(-|.)\d{3}(-|.)\d{4}$)/)

should do the trick for all cases.

You could also use:

(/((\d{3}(-|.)){2}\d{4}$)/)

but that will produce +ve values if extra characters are
added to the front of the test string - only zero (0) will
be a correct result or any non-zero value a fail. For the
sake of saving a few characters, I don't think it's worth
it.

Cheers.

[Michael Winter]

On 28 Sep 2004 15:45:51 -0700, Ward Cleaver <fr*******@yahoo.com> wrote:

Hi. I have an assignment
If you mean an educational course assignment, you're probably required to
mention that you received help.
to do some validating of a form using javascript and mostly the search()
method.
String.prototype.search is generally unsuitable for validation. If you
want to assert that a string matches a pattern, use RegExp.prototype.test:

/<pattern>/.test(<string>)

which returns true for a match. The search method returns the position
where a match was found.
I'm having problems getting a positive validation for phone numbers like
"123-456-7890" and "123.456.7890" but not like "123.456-7890". The
regular expression I'm using now is something like this:
ok = pn.search(/(^\d{3}-\d{3}-\d{4}$)|(^\d{3}.\d{3}.\d{4}$)/);
An unescaped dot (period) matches *any* character (except line
terminators). A literal dot needs to written with a backslash prefix.
Which to me looks like it SHOULD do what I want it to and not come back
with an ok=0 for a phone number using both hyphens and periods.
Please help.

Though I recommended the test method, I'd probably use
RegExp.prototype.exec so I could check that the separators match:

var r = /^\d{3}([.-])\d{3}([.-])\d{4}$/.exec(pn);

/* If the string didn't match, r will be null.
* If it did match, r will be an array with element
* 0 containing the match
* 1 containing the first remembered match (marked with
* parentheses)
* 2 containing the second remembered match
*/
if(r && (r[1] == r[2])) {
// Pattern matched and the separators are equal.
}

Good luck,
Mike

--
Michael Winter
Replace ".invalid" with ".uk" to reply by e-mail.

[rh]

"Michael Winter" wrote:
<...>

Though I recommended the test method, I'd probably use
RegExp.prototype.exec so I could check that the separators match:

var r = /^\d{3}([.-])\d{3}([.-])\d{4}$/.exec(pn);

/* If the string didn't match, r will be null.
* If it did match, r will be an array with element
* 0 containing the match
* 1 containing the first remembered match (marked with
* parentheses)
* 2 containing the second remembered match
*/
if(r && (r[1] == r[2])) {
// Pattern matched and the separators are equal.
}

Alternatively, including a backreference in the regular expression
would allow use of the preferred test method, e.g.:

if ( /^\d{3}([-.])\d{3}\1\d{4}$/.test(pn) ) {
// Pattern matched and the separators are equal.
}

../rh

[Michael Winter]

On 29 Sep 2004 09:20:10 -0700, rh <co********@yahoo.ca> wrote:

[snip]

Alternatively, including a backreference in the regular expression would
allow use of the preferred test method, e.g.:

I didn't know they existed as an ECMA-262 conformant pattern but I have
just found it (section 15.10.2.11). How well supported are they?

Thanks,
Mike

--
Michael Winter
Replace ".invalid" with ".uk" to reply by e-mail.

[Dr John Stockton]

JRS: In article <f7**************************@posting.google.com >,
dated Tue, 28 Sep 2004 15:45:51, seen in news:comp.lang.javascript, Ward
Cleaver <fr*******@yahoo.com> posted :

I have an assignment to do some validating of a form using
javascript and mostly the search() method. I'm having problems
getting a positive validation for phone numbers like "123-456-7890"
and "123.456.7890" but not like "123.456-7890". The regular
expression I'm using now is something like this:
ok = pn.search(/(^\d{3}-\d{3}-\d{4}$)|(^\d{3}.\d{3}.\d{4}$)/);
Which to me looks like it SHOULD do what I want it to and not come
back with an ok=0 for a phone number using both hyphens and periods.

Dot matches any character; use \. . Testing only with more-or-less
valid data is a distressingly common mistake; a test with a non-allowed
first separator would have given a clue. Build up such expressions in
small stages, testing as you go.

Search returns a number; to get a Boolean for OK, use test.

OK = /^(\d\d\d)([-\.])(\d\d\d)\2(\d\d\d\d)$/.test(pn)

Be aware that by using that format only you exclude many of the
telephones in North America and elsewhere.

--
© John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v4.00 IE 4 ©
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[rh]

"Michael Winter" <M.******@blueyonder.co.invalid> wrote in message news:<opse3j52gcx13kvk@atlantis>...

On 29 Sep 2004 09:20:10 -0700, rh <co********@yahoo.ca> wrote:

[snip]

Alternatively, including a backreference in the regular expression would
allow use of the preferred test method, e.g.:

I didn't know they existed as an ECMA-262 conformant pattern but I have
just found it (section 15.10.2.11). How well supported are they?

RegExp backreferences were present in v1.2. I believe it's possible to
use said same with gay abandon :).

../rh