Uncaught TypeError: Cannot read property '1' of null(…) in a JavaScript function

Question

This method is part of a module; And despite the error...

Uncaught TypeError: Cannot read property \'1\' of null(…)

works to a small degree, howeve

Answer 1

String#match returns either null (no match) or an array with the matches.

var domain = link.href.match(/(https?:\/\/.+?)\//)[1];
//                     ^^^^^

Workaround with check

var domain = link.href.match(/(https?:\/\/.+?)\//);

if (domain) {
    // do something with domain[1]
}