javascript 格式日期为清晰格式

Question

I have this code which is getting me the date in a ledgible format but it currently outputs this format 20200819 but I want to convert it to 2020-08-19 is this possible?

This is my code

const dateConverter = (dateIn) => {
    var yyyy = dateIn.getFullYear();
    var mm = dateIn.getMonth() + 1; // getMonth() is zero-based
    var dd = dateIn.getDate();
    return String(10000 * yyyy + 100 * mm + dd); // Leading zeros for mm and dd
}
  
var today = new Date();
console.log(dateConverter(today));

Answer 1

You don't need the converter function for that. Just use toLocaleDateString with a locale that has this format, like Sweden.

To get more certainty about the format, I have added two extensions:

 console.log(new Date().toLocaleDateString("en-se")); // To be explicit about the format of the numerical parts console.log(new Date().toLocaleDateString("en-se", { year: "numeric", month: "2-digit", day: "2-digit" }) ); // To be explicit about the delimiter also: console.log(new Date().toLocaleDateString("en-se", { year: "numeric", month: "2-digit", day: "2-digit" }).replace(/\D/g, "-") );

Alternative:

If you don't want to rely on the native toLocaleDateString function, then replace the following line in your code:

return String(10000 * yyyy + 100 * mm + dd)

with:

return String(10000 * yyyy + 100 * mm + dd).replace(/(....)(..)(..)/,"$1-$2-$3");

Answer 2

You can use padStart to create your own string like below, but I would reccomend looking into the date-fns or moment.js libraries, as they can handle this very nicely.

 const dateConverter = (dateIn) => { var year = dateIn.getFullYear(); var month = dateIn.getMonth() + 1; // getMonth() is zero-based var day = dateIn.getDate(); return year + "-" + month.toString().padStart(2, "0") + "-" + day.toString().padStart(2, "0"); } var today = new Date(); console.log(dateConverter(today));

Answer 3

You could use template literals to get the format you want, im pretty sure their must be a simpler way but, this is as similar to your code as possible

    const dateConverter = (dateIn) => {
  var yyyy = dateIn.getFullYear();
  var mm = dateIn.getMonth() + 1;
  if (mm < 10) mm = `0${mm}`; // getMonth() is zero-based
  var dd = dateIn.getDate();
  if (dd < 10) dd = `0${dd}`;
  return `${yyyy}-${mm}-${dd}`;
};

var today = new Date();
console.log(dateConverter(today));

Output as today: 2020-08-19

Answer 4

new Date().toISOString().slice(0, 10).split('-').reverse().join('/')




//use following date format methods and options.
var date = new Date(Date.UTC(2012, 11, 20, 3, 0, 0));

// formats below assume the local time zone of the locale;
// America/Los_Angeles for the US

// US English uses month-day-year order
console.log(date.toLocaleDateString('en-US'));
// → "12/19/2012"

// British English uses day-month-year order
console.log(date.toLocaleDateString('en-GB'));
// → "20/12/2012"

// Korean uses year-month-day order
console.log(date.toLocaleDateString('ko-KR'));
// → "2012. 12. 20."

// Event for Persian, It's hard to manually convert date to Solar Hijri
console.log(date.toLocaleDateString('fa-IR'));
// → "۱۳۹۱/۹/۳۰"

// Arabic in most Arabic speaking countries uses real Arabic digits
console.log(date.toLocaleDateString('ar-EG'));
// → "٢٠‏/١٢‏/٢٠١٢"

// for Japanese, applications may want to use the Japanese calendar,
// where 2012 was the year 24 of the Heisei era
console.log(date.toLocaleDateString('ja-JP-u-ca-japanese'));
// → "24/12/20"

// when requesting a language that may not be supported, such as
// Balinese, include a fallback language, in this case Indonesian
console.log(date.toLocaleDateString(['ban', 'id']));
// → "20/12/2012"

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleDateString