React JS how to add some day with current date

React JS how to add some day with current date

let startdate = moment(new Date()).format("YYYY-MM-DD");

var new_date = moment(startdate, "DD-MM-YYYY").add('days', 10);

var day = new_date.format('DD');

var month = new_date.format('MM');

var year = new_date.format('YYYY');

let Expairday = year + '-' + month + '-' + day;

alert(startdate + '----dddd----' + Expairday)