RegEx for any number of white spaces or digits, with a total length of 13

Question

I am working on a RegEx in which I want any number of occurrences of white spaces and any number of occurrences of digits in the total length of 13. Something like

'           12'

or

'       115678'

Current Regex:

(^\s*\d[0-9]{1,12})$

How to get this variable occurrences using blocks

My data is right aligned filled with blanks in the left. No just reg ex — Garima Goel, Sep 10 '16 at 14:27
So you've got, a bunch of spaces followed by a bunch of digits and you want the _whole thing_ (spaces and digits) to be up to 13 characters long, correct? — redneb, Sep 10 '16 at 14:29

chris85 · Answer 1 · 2016-09-10T14:49:22.883

You can allow upto 13 spaces and/or numbers with a character class:

^[\t \d]{1,13}$

If white spaces also includes new lines use the \s meta character in place of the space and \t.

^[\s\d]{1,13}$

If this is PHP you can use \h for horizontal whitespaces, Javascript doesn't support that.

^[\h\d]{1,13}$

A demo (of version 2): https://regex101.com/r/gZ9rA8/1

Non regex PHP version:

$string = '       115678';
if(strlen($string) <=13 && is_numeric($string)) {
    echo 'It\'s GOOD!';
}

https://eval.in/639391

Non regex javascript:

var string = '       111578';
if(string.length <= 13 && !isNaN(string.trim())) {
     alert('good');
} else {
    alert('bad')
}

Demo: https://jsfiddle.net/h9mx0tmn/

score 0 · Answer 2 · edited May 23 '17 at 11:51

0

Since there are two conditions to be met:-

any occurrences of white spaces followed by any occurrences of digits
total length of 13

Use positive look ahead regex like this:-

/(?=^\s*\d*$)(^.{13}$)/

Visit here for more about positive look ahead regex:-

Regex lookahead, lookbehind and atomic groups

Hope this helps.

edited May 23 '17 at 11:51

Community

1
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answered Sep 10 '16 at 15:17

Capital C

319
3
13

This matches any string in format of `\s*\d+.*` up to 13 characters. – revo Sep 10 '16 at 15:23
Edited the quantifier of the first condition. – Capital C Sep 10 '16 at 15:27
You didn't get me. It also matches ` 6ABCDEFGHIJK` – revo Sep 10 '16 at 15:36
@revo How if I move the start stop anchors into both conditions? Thanks for your guide. – Capital C Sep 10 '16 at 15:42
@CapitalC Your regex will work ok, just it seems more efficient to check the length first. – Wiktor Stribiżew Sep 10 '16 at 16:15
Noted and thanks. I'm glad that I can try help and learn at the same time. – Capital C Sep 10 '16 at 16:21

score -1 · Answer 3 · answered Sep 10 '16 at 14:36

-1

You could do with one huge ugly and inefficient regular expression:

^\s{0}\d{13}|\s{1}\d{12}|\s{2}\d{11}|\s{3}\d{10}|\s{4}\d{9}|\s{5}\d{8}|\s{6}\d{7}|\s{7}\d{6}|\s{8}\d{5}|\s{9}\d{4}|\s{10}\d{3}|\s{11}\d{2}|\s{12}\d{1}$

I would recommend against doing it this way though. Instead, you should do something like that: check the string against the regular expression ^\s{0,13}\d{0,13}$ and then verify that its length is 13 in a separate step.

answered Sep 10 '16 at 14:36

redneb

21,794
6
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2

Or simply `^(?=.{13}$)\s*\d*$` – revo Sep 10 '16 at 15:12
"I would recommend against doing it this way " - so would I. Especially, when there are a couple of simpler regular expressions covering the same. – Jan Sep 10 '16 at 15:14
@revo Good one. +1 – redneb Sep 10 '16 at 15:15
@revo Your answer is the best. Thanks. – Capital C Sep 10 '16 at 15:59

RegEx for any number of white spaces or digits, with a total length of 13

3 Answers3