1、金额进行千分

function commafy(num) {

    if ((num + "").trim() == "") {

        return "";

    }

    if (isNaN(num)) {

        return "";

    }

    num = num + "";

    if (/^.*\..*$/.test(num)) {

        const pointIndex = num.lastIndexOf(".");

        const intPart = num.substring(0, pointIndex);

        const pointPart = num.substring(pointIndex + 1, num.length);

        intPart = intPart + "";

        const re = /(-?\d+)(\d{3})/

        while (re.test(intPart)) {

            intPart = intPart.replace(re, "$1,$2")

        }

        num = intPart + "." + pointPart;

    } else {

        num = num + "";

        const re = /(-?\d+)(\d{3})/

        while (re.test(num)) {

            num = num.replace(re, "$1,$2")

        }

    }

    return num;

}

2、toFixed()保留两位小数丢失精度解决办法

function toFixedTwo(num) {

        return (num*100).toFixed(0)/100

}