Question

for example:

var s = '3+3';
s.replace(/([\d.]+)([\+\-)([^,]*)/g,
        function(all, n1, operator, n2) {
                r = new Number(n1) ??? new Number(n2);
                return r;
        }
);

note: not using eval()

Answer 1

Are Variable Operators Possible?

Not possible out of the box, but he gives a nice implementation to do it, as follows. Code by delnan.

var operators = {
    '+': function(a, b) { return a + b },
    '<': function(a, b) { return a < b },
     // ...
};

var op = '+';
alert(operators[op](10, 20));

So for your implementation

r = operators[operator](new Number(n1), new Number(n2));