Javascript正则表达式在_和-之间找到字符串

Question

I'm trying to work out the regex to get the en part of the string word_en-gb

I'm using .match(); eg

var string = "word_en-gb";
string.match(/(?<=\_)(.*?)(?=\-)/);

This (?<=\\_)(.*?)(?=\\-) works on regex101.com but when I use it in my code I get the error Uncaught SyntaxError: Invalid regular expression: /(?<=_)(.*?)(?=-)/: Invalid group

and

\\_(.*?)\\- matches on regex101 but produces _en-,en

Answer 1

Lookbehind isn't available in Javascript regex. You can use captured group #1:

var string = "word_en-gb";
string.match(/_(.*?)(?=-)/);
//=> ['_en', 'en']

Or negation:

string.match(/_([^-]*)/);
//=> ['_en', 'en']