问题:数字要保留两位小数,但是重写toFixed,大部分数据已经可以四舍五入,但是1.005类似的数据,四舍五入之后得到的数据是1.00,其实应该是1.01,求大神指点;

Number.prototype.toFixed = function (num) {

var changenum = (Number(this * Math.pow(10, num) + 0.5) / Math.pow(10, num)).toString(); index = changenum.indexOf("."); if (index < 0 && num > 0) { changenum = changenum + "."; for (i = 0; i < num; i++) { changenum = changenum + "0"; } } else { index = changenum.length - index; for (i = 0; i < (num - index) + 1; i++) { changenum = changenum + "0"; } } return changenum;

};