Calculate string value in javascript not using eval

Question

Is there a JavaScript method other than eval() for calculating a formula contained in a string?

Normally, I'd take action similar to

var apa = "12/5*9+9.4*2";
console.log(eval(apa));

So, does anyone know of any eval() alternatives?

Answer 1

You could use the Function() constructor:

function evil(fn) {
  return new Function('return ' + fn)();
}

console.log(evil('12/5*9+9.4*2')); // => 40.4