Displaying date to month dd, yyyy

问题

given time_cancel = 2019-01-06T23:29:35.000Z, would like to format it to month dd, yyyy (in this example, it is January 06, 2019)

In the following code, I have to write 12 if else block to convert mm to month i.e. in this case, is to convert 01 to January.

is there a better /faster way to convert time_cancel to format month dd, yyyy in Javascript or Typescript/es6/react. Thanks in advance!

let date = time_cancel.split("T")[0];
var dateArray = date.split("-"); 
var month;

// 12 if else code
if(dateArray[1]=='01') month='January';
else if(dateArray[1]=='02') month='February';
 ....
else if (dateArray[1]=='12') month='December;

var res=month+" "+dateArray[2]+", "+dateArray[0];

回答1:

.toLocaleDateString() can give you DD Month YYYY, but it doesn't let you customise the order. I would be very tempted to stick with this default behaviour, but you can chop it up if your really must. You still profit from the locale awareness and translations...

const formattedDate = new Date("2019-01-06T23:29:35.000Z")
.toLocaleDateString({},
  {timeZone:"UTC",month:"long", day:"2-digit", year:"numeric"}
  )
  console.log(formattedDate)
const sp = formattedDate.split(' ')
console.log(`${sp[1]} ${sp[0]}, ${sp[2]}`)

回答2:

You can make an array like

let months = ["January", "February", "March", /*etc*/];

Read about getMonth()

lets say you have a date let date = new Date();

Simply do let m = date.getMonth() and it will return values from 0 to 11.

Then you can just say months[m] and you will get your desired date.

Here is a JSFiddle, feel free to edit the months in date to check it's validity. http://jsfiddle.net/snqwg7vd/

回答3:

function formatraw(date, format, utc) {

    let raw = new Date(date.split(" ").join("T"));

    let res = format.slice();

    const MMMM = ["\x00", "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
    const MMM = ["\x01", "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
    const dddd = ["\x02", "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
    const ddd = ["\x03", "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];

    function ii(i, len) {
        let s = i + "";
        len = len || 2;
        while (s.length < len) s = "0" + s;
        return s;
    }

    const y = utc ? raw.getUTCFullYear() : raw.getFullYear();
    res = res.replace(/(^|[^\\])yyyy+/g, "$1" + y);
    res = res.replace(/(^|[^\\])yy/g, "$1" + y.toString().substr(2, 2));
    res = res.replace(/(^|[^\\])y/g, "$1" + y);

    const M = (utc ? raw.getUTCMonth() : raw.getMonth()) + 1;
    res = res.replace(/(^|[^\\])MMMM+/g, "$1" + MMMM[0]);
    res = res.replace(/(^|[^\\])MMM/g, "$1" + MMM[0]);
    res = res.replace(/(^|[^\\])MM/g, "$1" + ii(M));
    res = res.replace(/(^|[^\\])M/g, "$1" + M);

    const d = utc ? raw.getUTCraw() : raw.getDate();
    res = res.replace(/(^|[^\\])dddd+/g, "$1" + dddd[0]);
    res = res.replace(/(^|[^\\])ddd/g, "$1" + ddd[0]);
    res = res.replace(/(^|[^\\])dd/g, "$1" + ii(d));
    res = res.replace(/(^|[^\\])d/g, "$1" + d);

    const H = utc ? raw.getUTCHours() : raw.getHours();
    res = res.replace(/(^|[^\\])HH+/g, "$1" + ii(H));
    res = res.replace(/(^|[^\\])H/g, "$1" + H);

    const h = H > 12 ? H - 12 : H == 0 ? 12 : H;
    res = res.replace(/(^|[^\\])hh+/g, "$1" + ii(h));
    res = res.replace(/(^|[^\\])h/g, "$1" + h);

    const m = utc ? raw.getUTCMinutes() : raw.getMinutes();
    res = res.replace(/(^|[^\\])mm+/g, "$1" + ii(m));
    res = res.replace(/(^|[^\\])m/g, "$1" + m);

    const s = utc ? raw.getUTCSeconds() : raw.getSeconds();
    res = res.replace(/(^|[^\\])ss+/g, "$1" + ii(s));
    res = res.replace(/(^|[^\\])s/g, "$1" + s);

    let f = utc ? raw.getUTCMilliseconds() : raw.getMilliseconds();
    res = res.replace(/(^|[^\\])fff+/g, "$1" + ii(f, 3));
    f = Math.round(f / 10);
    res = res.replace(/(^|[^\\])ff/g, "$1" + ii(f));
    f = Math.round(f / 10);
    res = res.replace(/(^|[^\\])f/g, "$1" + f);

    const T = H < 12 ? "AM" : "PM";
    res = res.replace(/(^|[^\\]){TT}/g, "$1" + T);
    res = res.replace(/(^|[^\\]){T}/g, "$1" + T.charAt(0));

    const t = T.toLowerCase();
    res = res.replace(/(^|[^\\]){tt}/g, "$1" + t);
    res = res.replace(/(^|[^\\]){t}/g, "$1" + t.charAt(0));

    let tz = -raw.getTimezoneOffset();
    let K = utc || !tz ? "Z" : tz > 0 ? "+" : "-";
    if (!utc) {
        tz = Math.abs(tz);
        let tzHrs = Math.floor(tz / 60);
        let tzMin = tz % 60;
        K += ii(tzHrs) + ":" + ii(tzMin);
    }
    
    res = res.replace(/(^|[^\\])K/g, "$1" + K);

    const day = (utc ? raw.getUTCDay() : raw.getDay()) + 1;
    res = res.replace(new RegExp(dddd[0], "g"), dddd[day]);
    res = res.replace(new RegExp(ddd[0], "g"), ddd[day]);

    res = res.replace(new RegExp(MMMM[0], "g"), MMMM[M]);
    res = res.replace(new RegExp(MMM[0], "g"), MMM[M]);

    res = res.replace(/\\(.)/g, "$1");

    return res;
}

console.log(formatraw("2019-01-06T23:29:35.000Z","MMMM dd, yyyy"))

来源：https://stackoverflow.com/questions/54231505/displaying-date-to-month-dd-yyyy

标签

javascript

ecmascript-6