javascript match() error

Question

I'm trying to count # of lines of a pre element and I'm using this:

var numlines = $('#mypreelement').text().match(/\n\r?/g).length + 1;

it works, but in some situations I get a error

Error: $('#mypreelement').text().match(/\n\r?/g) is null

this only happens on certain pages, but these pages don't have anything different from the ones on which it works, besides content of course...

Why?

The answer from this question (http://stackoverflow.com/questions/2035910/how-to-get-the-number-of-lines-in-a-textarea) has a regex for matching cross-browser hard returns. — Mottie, Apr 06 '11 at 03:17

alex · Accepted Answer · 2011-04-06T03:59:18.317

7

That means it couldn't match any of them, and null does not have a length property.

So try this...

if (var lines = $('#mypreelement').text().match(/\n\r?/g) != null) {
   var linesLength = lines.length + 1;
}

edited Apr 06 '11 at 03:59

answered Apr 06 '11 at 02:38

alex

score 3 · Answer 2 · answered Apr 06 '11 at 02:40

3

If the regular expression includes the g flag, the method returns an Array containing all matches. If there were no matches, the method returns null.

answered Apr 06 '11 at 02:40

epascarello

2 Answers2