Extracting Strings Into an Array Regex

Question

I'm almost there! Just can't figure out the last part of what I need... forming the array.

I want to go through an html file and extract url's from between the phrases playVideo(' and ')

For testing purposes I am just trying to get it to work on the variable str, eventually this will be replaced by the html document:

<script type="text/javascript">
    var str ="playVideo('url1') BREAK playVideo('url2') BREAK playVideo('url3')"; 

    var testRE = str.match("playVideo\\(\'(.*?)\'");

    alert(testRE[1]);
</script>

This will output 'url1' but if I change it to alert(testRE[2]) it is undefined. How can I get it to fill out the array with all of the URLs (eg testRE[2] output 'url2' and so on) ?

Thanks for any help, new to regex.

http://stackoverflow.com/questions/6825492/javascript-str-search-multiple-instances — , Jan 31 '12 at 00:48
Thanks for the link Ben but I don't see how that applies. I won't know what string I'm looking for since they will all eventually be various urls, so how could I indexOf for an unknown string? — dougmacklin, Jan 31 '12 at 00:59
Read the page--you look for that playVideo part of the string, it places you right at the start of each url you are looking for in succession. — , Jan 31 '12 at 05:06

score 3 · Answer 1 · answered Jan 31 '12 at 01:07

3

Cannot comment, why is that, but adding that by iterating on the regex you get access to the groups;

var str ="playVideo('url1') BREAK playVideo('url2') BREAK playVideo('url3')";
var re = /playVideo\('(.*?)'\)/g;
while (match = re.exec(str)) {
    alert(match[1]);
}

answered Jan 31 '12 at 01:07

Carl Krig

161
7

thank you very much carl. I'll go read up on exec. much appreciated. – dougmacklin Jan 31 '12 at 01:32

David Clarke · Accepted Answer · 2012-01-31T01:09:19.977

2

Normally a javascript regular expression will just perform the first match. Update your regular expression to add the g modifier. Unfortunately JavaScript regular expressions don't have a non-capturing group so you have to do a little more processing to extract the bit you want e.g.

<script type="text/javascript">
var str ="playVideo('url1') BREAK playVideo('url2') BREAK playVideo('url3')"; 

var testRE = str.match(/playVideo\(\'[^']*\'/g);
var urls = [];
for (var i = 0; i < testRE.length; i++)
{
    urls[i] = testRE[i].substring(11).match(/[^']*/);
}

alert(urls[1]);
alert(urls[2]);
</script>

edited Jan 31 '12 at 01:09

answered Jan 31 '12 at 00:43

David Clarke

12,888
9
86
116

this is so close! only problem is now it is outputting "playvideo('url1" for testRE[0] and "playvideo('url2" for testRE[1] whereas I just want "url1" and "url2" – dougmacklin Jan 31 '12 at 00:54
@Dougie Bear - If its working so far, try `/playVideo\('([^']*)'/g` or `/playVideo\(\'([^']*)\'/g` – Jan 31 '12 at 01:05
those both still leave in **playvideo('** which I need to scrap so that only the url remains – dougmacklin Jan 31 '12 at 01:09
Thanks @Dougie Bear. Carl Krig's answer is a useful alternative. Instead of using the _string.match()_ function you can use the _RegExp.exec()_ function and iterate through the matches. – David Clarke Jan 31 '12 at 01:14

Extracting Strings Into an Array Regex

2 Answers2