Regex exec() limit or interesting work

Question

Hello,
It says that exec is better and has has not the 9 limit:
https://forums.netiq.com/showthread....ctor-questions
I LiveDebug my new supa-dupa-cool firewall collector and I bumped into
the //.exec() limit, which is RegExp.$9. The RegExp.$10 is nothing.
But if I use variable=//.exec(); variable[10] than it is good. What is
the difference? I know it works and not works , but you know what I
mean. Is it a built-in something?
The RegExp.$9 value is the same as variables[9] value. variable[14] is
still good.
http://tinyurl.com/kalbhlk says that it is unlimited and I have to use
it variable=//.exec() instead what the Collector Developer tutorial
says.
Thank you for your answers!
woodspeed
woodspeed's Profile: https://forums.netiq.com/member.php?userid=7232
View this thread: https://forums.netiq.com/showthread.php?t=52416

Answer 1

On 12/15/2014 06:24 AM, woodspeed wrote:
>
> It says that exec is better and has has not the 9 limit:
> https://forums.netiq.com/showthread....ctor-questions
> I LiveDebug my new supa-dupa-cool firewall collector and I bumped into
> the //.exec() limit, which is RegExp.$9. The RegExp.$10 is nothing.
> But if I use variable=//.exec(); variable[10] than it is good. What is
> the difference? I know it works and not works , but you know what I
> mean. Is it a built-in something?
The biggest differences that I have found are:
1. .exec() returns an array with no limits in size; as a result, it is
probably always the best way to return captured groups.
2. .test() gives you a nice boolean (match or not) and then you happen to
be able to get captured groups from the global RegExp object, but only up
through $9 as you noticed.
There may be performance benefits going one way or another, but I've done
a very small, statistically-insignificant, amount of testing and not
noticed much difference when the match works. When matches fail and the
regexes are not anchored (meaning the regex engine tries really hard to
find a match, at the cost of performance) they both quickly perform
terribly; I do not remember if one was worse than the other.
Summary: Use .exec(), set to a variable, and then test for null if you wan
to know if it succeeded/failed.
Good luck.
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