1 /**
  2  * 지수 형태로 숫자를 표시<br>
  3  * number string to exponential form
  4  */
  5 String.prototype.toExponential = function () {//v1.0
  6     return this.replace(/^([+-])?(\d+).?(\d*)[eE]([-+]?\d+)$/, function (x, s, n, f, c) {
  7         var l = +c < 0, i = n.length + +c, x = (l ? n : f).length,
  8             c = ((c = Math.abs(c)) >= x ? c - x + l : 0),
  9             z = (new Array(c + 1)).join("0"), r = n + f;
 10         return s + (l ? r = z + r : r += z).substr(0, i += l ? z.length : 0) + (i < r.length ? "." + r.substr(i) : "");
 11     });
 12 };