将dd.mm.yyyy格式转换为yyyy-mm-dd

Question

How can I convert dd.mm.yyyy format date to yyyy-mm-dd format in JavaScript?

Here is an example:

30.01.2010
to 
2010-01-30

Meaning convert dmY to Ymd. I know how to do this in PHP but I need it in JavaScript.

Answer 1

You can do this pretty simply. Just split the european date into an array, reverse it, and then join it with dashes.

var euro_date = '30.01.2010';
euro_date = euro_date.split('.');
var us_date = euro_date.reverse().join('-');

Answer 2

Datejs can parse that. The code is at http://datejs.googlecode.com/files/date.js

EDIT: It is not safe to left date.js determine the format string automatically. I made the mistake of not testing with a day <= 12 (duh). You should use:

Date.parseExact('09.01.2010', 'd.M.yyyy').toString('yyyy-MM-dd');

or

Date.parseExact('09.01.2010', 'dd.MM.yyyy').toString('yyyy-MM-dd');

depending on whether you want to allow single digit days.

Answer 3

Datejs is a bit bloated if you only need to do this. You can use split() and concatenate the results:

var eu_date = '30.01.2010';
var parts = eu_date.split('.');
var us_date = parts[2]+'-'+parts[1]+'-'+parts[0];

For these kinds of conversions where no date logic is needed, it's usually smartest to just use string manipulation tools.

Answer 4

    function stringToDate( value ) {
      var isEuro = value.match( /^\d{1,2}\.\d{1,2}\.\d{4}$/ )
      var isIso = value.match( /^\d{4}-\d{1,2}-\d{1,2}$/ )

      if ( isEuro ) {
        value = value.split('.')
        value = [value[2],value[1],value[0]].join('-') //.reverse() isn't working in IEdge
        isIso = true
      }

      if ( isEuro || isIso ) {
        var date = new Date( value )
      }

      if ( isNaN( date.getTime() ) || !isIso ) {
         return false
      }


      return date
    }

    stringToDate('30.01.2000') //Sun Jan 30 2000 00:00:00 GMT+0100 (CET)
    stringToDate('30.1.2000') //Sun Jan 30 2000 01:00:00 GMT+0100 (CET)
    stringToDate('2000-01-30') //Sun Jan 30 2000 01:00:00 GMT+0100 (CET)
    stringToDate('2000-1-30') //Sun Jan 30 2000 01:00:00 GMT+0100 (CET)