Get string inside parentheses, removing parentheses, with regex

Question

I have these two strings...

var str1 = \"this is (1) test\";
var str2 = \"this is (2) test\";

And want to write a RegEx to extract what is

Answer 1

try this

    var re = (/\((.*?)\)/g);

    var str1 = str1.match(/\((.*?)\)/g);
    var new_str1=str1.substr(1,str1.length-1);
    var str2 = str2.match(/\((.*?)\)/g);
    var new_str2=str2.substr(1,str2.length-1);

    var str3 = new_str1+new_str2; //produces "12"