1.005*100=100.5，Math.round四舍五入，得101再除100得1.01，能不能这样

写的不大细

<script>
    function change(num) {
                if(typeof num != 'number') {
                    return
                }
                var numStr = num.toString();
                var index = numStr.indexOf('.')
                if(index == -1) {
                    return numStr += '.00'
                } else if(numStr.length - index == 2) {
                    return numStr += '0'
                } else if(numStr.length - index == 3) {
                    return numStr
                } else {
                    var reg = /.(\d{3})\d*$/;
                    newNum = numStr.replace(reg, function($0, $1) {
                        //tempDec 用来判断四舍五入后小数位数
                        var tempDec = Math.round(Number($1.substring(0, 2) + '.' + $1.substring(2)));
                        var newDec;
                        tempDec = tempDec.toString();
                        tempDec == 0 ? newDec = '00' : (tempDec.length == 1 ? newDec = '0' + tempDec : newDec = tempDec)
                        return '.' + newDec
                    })
                }
                return newNum
            }
    </script>

将var reg = /.(d{3})d+$/;改为了var reg = /.(d{3})d*$/;
num != Number改为num != 'number'

function change(money){
    if(typeof money != 'number')return -1;
    return (100*money).toFixed(0)/100;
}
console.log(change(3.005));