javascript 浮點運算函數

//浮點數相加
function float_add(arg1, arg2){
  var r1, r2, m;
  try { r1 = arg1.toString().split(".")[1].length; } catch (e) { r1 = 0; }
  try { r2 = arg2.toString().split(".")[1].length; } catch (e) { r2 = 0; }
  m = Math.pow(10, Math.max(r1, r2));
  return (FloatMul(arg1, m) + FloatMul(arg2, m)) / m;
}


//浮點數相減
function float_sub(arg1, arg2){
  var r1, r2, m, n;
  try { r1 = arg1.toString().split(".")[1].length } catch (e) { r1 = 0 }
  try { r2 = arg2.toString().split(".")[1].length } catch (e) { r2 = 0 }
  m = Math.pow(10, Math.max(r1, r2));
  n = (r1 >= r2) ? r1 : r2;
  return ((arg1 * m - arg2 * m) / m).toFixed(n);
}

//浮點數相乘
function float_mul(arg1, arg2){
  var m = 0, s1 = arg1.toString(), s2 = arg2.toString();
  try { m += s1.split(".")[1].length; } catch (e) { }
  try { m += s2.split(".")[1].length; } catch (e) { }
  return Number(s1.replace(".", "")) * Number(s2.replace(".", "")) / Math.pow(10, m);
}


//浮點數相除
function float_div(arg1, arg2){
  var t1 = 0, t2 = 0, r1, r2;
  try { t1 = arg1.toString().split(".")[1].length } catch (e) { }
  try { t2 = arg2.toString().split(".")[1].length } catch (e) { }
  with (Math){
    r1 = Number(arg1.toString().replace(".", ""));
    r2 = Number(arg2.toString().replace(".", ""));
    return (r1 / r2) * pow(10, t2 - t1);
  }
}