How to do calculations inside input in javascript?

Question

JavaScript

The script takes a number from input, performs some calculations on it, and outputs the result.
It would be more convenient to fill this input with something like "16384 + 256" so that the script takes this amount and goes on working.
"But how, Holmes?" ©

Answer 1

The easiest option:

var value = '(5+7)*10';
var res = new Function('return ' + value);

console.log(res()) // => 210