Accessing $1 etc. outside of string.replace() in javascript regex?

Question

As we all know $1 and so on are backreferences to captured groups in a string.replace() when using a regex, so you can do something like:

string.replace(/(http:\/\/\S*)/g, '<a href="$1" target="_blank">link<\/a>')

Now my question is whether there is a way to access the captured data in $1 and so on OUTSIDE the replace. Like backrefarray[1] for $1 or something...

Is such thing possible and how?

score 2 · Answer 1 · answered Dec 09 '12 at 15:27

2

Yes, you can use match :

var array = str.match(/(http:\/\/\S*)/g);

(but the array starts at index 0)

answered Dec 09 '12 at 15:27

Denys Séguret

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Nice, thanks. However Gumbo's answer is a little better for my case. +1 – Wingblade Dec 09 '12 at 15:29

score 2 · Accepted Answer · answered Dec 09 '12 at 15:28

2

You can use a function for replacement instead of a fixed string:

string.replace(/(http:\/\/\S*)/g, function() {
    return '<a href="'+arguments[1]+'" target="_blank">link<\/a>';
})

The matches of the whole pattern and of each group are passed as arguments to the function.

answered Dec 09 '12 at 15:28

Gumbo

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Thanks, I can use this. +1 and accepted(or at least I will once the 10 minutes are over)! – Wingblade Dec 09 '12 at 15:30

score 1 · Answer 3 · answered Dec 09 '12 at 17:18

1

RegExp.$1

Also, after any regexp operation is finished, the $1, $2 capture variables, (if they exist), are available globally as properties of the global RegExp object. Try this out after a successful match:

alert(RegExp.$1);

answered Dec 09 '12 at 17:18

ridgerunner

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Accessing $1 etc. outside of string.replace() in javascript regex?

3 Answers3

RegExp.$1