日期函数传递未定义的对象

Question

function addDays(date, days) {

          var result = new Date(date);
          console.log("initialdate"+result);
          result.setDate(result.getDate() + days);
          result=result.toLocaleDateString();
          result = result.split(' ')[0];
          return result;
     }

I am trying to add days to a date, however when I convert a date into object I get an error as Invalid date

This is the HTML code.

<div class="form-line"> <label for="date">Date</label> <input type="text" class="form-control datepicker" id="edit_date" placeholder="Enter Date" required="true" value>

Answer 1

The problem that you are having is your input format. For parsing to work the format will need to be either YYYY/MM/DD or MM/DD/YYYY .

 function addDays(date, days) { var result = new Date(date); console.log("initialdate: "+result); result.setDate(result.getDate() + days); result=result.toLocaleDateString(); result = result.split(' ')[0]; console.log("return: "+result); return result; } addDays("05/25/2019", 5); addDays("2019/05/24", 5); 

Answer 2

To achieve expected result, use below option of changing date in 'DD/MM/YYYY' to valid ISO 8601 format for Date constructor

1. format date to new Date(YYYY, MM, DD) by splitting date in format -DD/MM/YYYY
2. Month value starts from 0 for Jan , decrease by 1 for getting valid month
3. Add days using setDate

 function addDays(date, days) { let fomarttedDate = date.split("/") var result = new Date(fomarttedDate[2], fomarttedDate[1] -1, fomarttedDate[0]); result.setDate(result.getDate() + days); result=result.toLocaleDateString(); result = result.split(' ')[0]; return result; } console.log(addDays("23/05/2019", 2)) 

Please refer this link for more details on datestring valid formats
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date
http://www.ecma-international.org/ecma-262/5.1/#sec-15.9.1.15

codepen for reference - https://codepen.io/nagasai/pen/zQvpaa