Test if string contains brackets with integer in it

Question

I want to test if a string in javascript contains normal brackets with an integer in it

var str="(12) this is a test";
var pat=/(([\d]+))/;
if (pat.test(str)) 
    alert("true");

Works fine, but it also returns true when the string looks like this

var str="12) test";
var str="(12 test";

which should return false.

Answer 1

Escape brackets with \:

/\([\d]+\)/.test(str);