如果字符匹配，则选择第N个字符-RegEx

Question

I feel like an idiot which is not uncommon but I am working with RegEx and I need to select the 8th and 9th character if the characters match my input. I have a working RegEx but it's not working with Javascript which I assume is due to the lookbehind?

What I have right now is the following:

RegEx:

(?<=^.{7})gg

This will match the 8th and 9th character if they contain 'gg'.

Any suggestions how I can get this working in Javascript?

Answer 1

Matching Groups solution

^.{7}(gg)

Select the second group

var myString = "gsagq3eqsvertwfeqh3qfggsdfgsdh";
var myRegexp = /^.{7}(gg)/g;
var match = myRegexp.exec(myString);
console.log(match[1]); // Error
myString = "gsagq3eggvertwfeqh3qfggsdfgsdh";
myRegexp = /^.{7}(gg)/g;
match = myRegexp.exec(myString);
console.log(match[1]); // gg

Group Selection from: https://stackoverflow.com/a/432503/

This code returns: gg on the second match

Explanation

^ Match the start of the string

.{6} Match any first 6 chars

(gg) Match the desired string in a group