时间格式化

const newDate = str => {
    if (str === null) return null;
    if (str === undefined) return new Date();
    if (str.constructor != String) return new Date(str);
    let $ = str.match(/^\s*(\d+)-(\d+)-(\d+)T(\d+):(\d+):(\d+)\s*$/);
    return $ && new Date($[1], $[2] - 1, $[3], $[4], $[5], $[6]) || new Date(str);
}
/**
 *  * 格式化时间
* 
* @param {String} str
 * @param {String} fmt  "yyyy-MM-dd hh:mm:ss"  "yyyy-MM-dd"
 * @returns 格式化后的时间
 */
const formatDate = (str, fmt) => {
    if (!Boolean(str)) {
        return ""
    }
    const now = newDate(str);
    let o = {
        "M+": now.getMonth() + 1,                 //月份 
        "d+": now.getDate(),                    //日 
        "h+": now.getHours(),                   //小时 
        "m+": now.getMinutes(),                 //分 
        "s+": now.getSeconds(),                 //秒 
        "q+": Math.floor((now.getMonth() + 3) / 3), //季度 
        "S": now.getMilliseconds()             //毫秒 
    };
    if (/(y+)/.test(fmt)) {
        fmt = fmt.replace(RegExp.$1, (now.getFullYear() + "").substr(4 - RegExp.$1.length));
    }
    for (let k in o) {
        if (new RegExp("(" + k + ")").test(fmt)) {
            fmt = fmt.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));
        }
    }
    return fmt;
}
export { formatDate, newDate }