如何将字符串转换为JavaScript日期对象?
var st = "date in some format"
var dt = new Date();
var dt_st = // st in Date format, same as dt.
如何将字符串转换为JavaScript日期对象?
var st = "date in some format"
var dt = new Date();
var dt_st = // st in Date format, same as dt.
当前回答
还有一种方法是在格式字符串上构建一个带有命名捕获组的正则表达式,然后使用该正则表达式从日期字符串中提取日、月和年:
function parseDate(dateStr, format) { const regex = format.toLocaleLowerCase() .replace(/\bd+\b/, '(?<day>\\d+)') .replace(/\bm+\b/, '(?<month>\\d+)') .replace(/\by+\b/, '(?<year>\\d+)') const parts = new RegExp(regex).exec(dateStr) || {}; const { year, month, day } = parts.groups || {}; return parts.length === 4 ? new Date(year, month-1, day) : undefined; } const printDate = x => console.log(x ? x.toLocaleDateString() : x); printDate(parseDate('05/11/1896', 'dd/mm/YYYY')); printDate(parseDate('07-12-2000', 'dd-mm-yy')); printDate(parseDate('07:12:2000', 'dd:mm:yy')); printDate(parseDate('2017/6/3', 'yy/MM/dd')); printDate(parseDate('2017-6-15', 'y-m-d')); printDate(parseDate('2015 6 25', 'y m d')); printDate(parseDate('2015625', 'y m d')); // bad format
其他回答
日期。解析几乎可以得到你想要的。它在上午/下午部分窒息,但通过一些黑客你可以让它工作:
var str = 'Sun Apr 25, 2010 3:30pm',
timestamp;
timestamp = Date.parse(str.replace(/[ap]m$/i, ''));
if(str.match(/pm$/i) >= 0) {
timestamp += 12 * 60 * 60 * 1000;
}
如果要从“dd/MM/yyyy”格式转换。这里有一个例子:
var pattern = /^(\d{1,2})\/(\d{1,2})\/(\d{4})$/;
var arrayDate = stringDate.match(pattern);
var dt = new Date(arrayDate[3], arrayDate[2] - 1, arrayDate[1]);
此解决方案适用于IE 9以下版本。
你可以使用regex解析字符串以详细的时间,然后创建日期或任何返回格式,如:
//example : let dateString = "2018-08-17 01:02:03.4"
function strToDate(dateString){
let reggie = /(\d{4})-(\d{2})-(\d{2}) (\d{2}):(\d{2}):(\d{2}).(\d{1})/
, [,year, month, day, hours, minutes, seconds, miliseconds] = reggie.exec(dateString)
, dateObject = new Date(year, month-1, day, hours, minutes, seconds, miliseconds);
return dateObject;
}
alert(strToDate(dateString));
还有一种方法是在格式字符串上构建一个带有命名捕获组的正则表达式,然后使用该正则表达式从日期字符串中提取日、月和年:
function parseDate(dateStr, format) { const regex = format.toLocaleLowerCase() .replace(/\bd+\b/, '(?<day>\\d+)') .replace(/\bm+\b/, '(?<month>\\d+)') .replace(/\by+\b/, '(?<year>\\d+)') const parts = new RegExp(regex).exec(dateStr) || {}; const { year, month, day } = parts.groups || {}; return parts.length === 4 ? new Date(year, month-1, day) : undefined; } const printDate = x => console.log(x ? x.toLocaleDateString() : x); printDate(parseDate('05/11/1896', 'dd/mm/YYYY')); printDate(parseDate('07-12-2000', 'dd-mm-yy')); printDate(parseDate('07:12:2000', 'dd:mm:yy')); printDate(parseDate('2017/6/3', 'yy/MM/dd')); printDate(parseDate('2017-6-15', 'y-m-d')); printDate(parseDate('2015 6 25', 'y m d')); printDate(parseDate('2015625', 'y m d')); // bad format
我使用这个函数将任何Date对象转换为UTC Date对象。
function dateToUTC(date) {
return new Date(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate(), date.getUTCHours(), date.getUTCMinutes(), date.getUTCSeconds());
}
dateToUTC(new Date());