JavaScript通过正则表达式匹配时间格式进行转换

//匹配时间格式：20190322T142523910（严格匹配）
var DATE_REGEXP = new RegExp("^(\\d{4})(\\d{2})(\\d{2})([T\\s](\\d{2})(\\d{2})(\\d{2})(\\d{3}))$");   

function toDate(dateString) {       
    if (DATE_REGEXP.test(dateString)) {           
        var timestamp = dateString.replace(DATE_REGEXP, function($all, $year, $month, $day, $part1, $hour, $minute, $second, $part2, $milliscond) {               
            var date = new Date($year, $month - 1, $day, $hour || "00", $minute || "00", $second || "00", $milliscond || "00");               
            return date.getTime();           
        });           
        var date = new Date();           
        date.setTime(timestamp);           
        return date;       
    }       
    return null;   
}