Question

I have this regex

var mregex = /(\$m[\w|\.]+)/g;
string mstring= "$m.x = $m.y";

So basically capture each instance of $m.[+ any number of alphanumeric or . until another character or the end]

I have this working in C# but I’m trying to port it over to javascript, so dropped the name capture.

var match = mregexp.exec(mstring);

match has
0: “$m.x”
1: “$m.x” // not $m.y as I would have expected.

What am i doing wrong?

thanks

Answer 1

You regular expression just matches once. The [0] element of the return array is the entire matched substring. The [1] element is the first group, which in your case is the same. You’d have to call .exec() again to get it to find the second instance.

You can pass a function to .replace(), which I personally like:

mstring.replace(mregexp, function(_, group) {
  console.log( group );
});

That’d show you both matched groups. (The function is passed arguments that are of the same nature as the elements of the returned array from .exec().)