Question

Why can’t I output my regex to a variable, and then run regex on it a second time?

I’m writing a greasemonkey javascript that grabs some raw data, runs some regex on it, then runs some more regex on it to refine the results:

// I tried this on :: http://stackoverflow.com/
var tagsraw = (document.getElementById("subheader").innerHTML);
alert(tagsraw);

Getting the raw data (above code) works

var trimone = tagsraw.match(/title\W\W\w+\s\w+\s\w+\s\w+\s\w+/g);
alert(trimone);

running regex once works (above code); but running (code below) doesn’t??

var trimtwo = trimone.match(/\s\w+\s\w+\s\w+\s\w+/g);
alert(trimtwo);

Can some advise me as to what is wrong with my code/approach?

Answer 1

The reason the first match works, is because innerHTML returns a string.

However the match returns an array, thus treat it as one:

for (var i=0; i<trimone.length; i++)
{
    var trimtwo = trimone[i].match(/\s\w+\s\w+\s\w+\s\w+/g);
    alert(trimtwo);
}

Edit:

Try this code instead though, I think this is a bit closer to what you want to achieve:

var trimone = tagsraw.match(/title\s*=\s*".*"/g);
alert(trimone);

for (var i=0; i<trimone.length; i++)
{
    alert(trimone[i]);
}