js数字转中文

突然有这么个需求，变量列表，索引现实为中文

    const toChinesNum = (num) => {
        let changeNum = ['零', '一', '二', '三', '四', '五', '六', '七', '八', '九']; //changeNum[0] = "零"
        let unit = ["", "十", "百", "千", "万"];
        num = parseInt(num);
        let getWan = (temp) => {
            let strArr = temp.toString().split("").reverse();
            let newNum = "";
            for (var i = 0; i < strArr.length; i++) {
                newNum = (i == 0 && strArr[i] == 0 ? "" : (i > 0 && strArr[i] == 0 && strArr[i - 1] == 0 ? "" : changeNum[strArr[i]] + (strArr[i] == 0 ? unit[0] : unit[i]))) + newNum;
            }
            return newNum;
        }
        let overWan = Math.floor(num / 10000);
        let noWan = num % 10000;
        if (noWan.toString().length < 4) noWan = "0" + noWan;
        return overWan ? getWan(overWan) + "万" + getWan(noWan) : getWan(num);

    };