Commenting Regular Expressions

Unfortunately, JavaScript doesn’t have a verbose mode for regular expression literals like some other langauges do. You may find this interesting, though.

In lieu of any external libraries, your best bet is just to use a normal string and comment that:

var r = new RegExp(
    '('      + //start capture
    '[0-9]+' + // match digit
    ')'        //end capture
); 
r.test('9'); //true