convert mm/dd/yyyy to yyyy-mm-dd in javascript code example

Example 1: javascript convert date to yyyy-mm-dd

// `date` is a `Date` object
const formatYmd = date => date.toISOString().slice(0, 10);

// Example
formatYmd(new Date());      // 2020-05-06

Example 2: javascript convert date from mm/dd/yyyy to yyyymmdd

var yourdate = date.split("/").reverse().join("-");

Example 3: convert date format from yyyy-mm-dd to dd-mm-yyyy using value javascript

date.value.split("-").reverse().join("-");      //"2021-01-17" --> 17-01-2021