Javascript using prototype how can I set the value of “this” for a number?

Question

So if we can get past the \"should you?\" question ... does anyone know how to set the value of an integer in prototype?

Answer 1

Number.prototype.add = function(num){
  var newVal = this.valueOf() + num;
  this.valueOf(newVal);
  return newVal;
}

var rad = new Number(4001.23);
document.write(rad.add(10) + '
' + rad);