Answers for "current year and previous year data show in js"

set a previous year to the current date in javascript

const d = new Date();
d.setFullYear(d.getFullYear()-1);

console.log(d.toDateString()); // "Fri Oct 04 2019"

current year javascript

var currentYear= new Date().getFullYear(); 

// should use moment library
https://momentjs.com/