how to get last two digits of a number in javascript code example

Example 1: js get last 4 digits

const id = "ctl03_Tabs1";
console.log(id.slice(id.length - 5)); //Outputs: Tabs1
console.log(id.slice(id.length - 1)); //Outputs: 1

Example 2: get last two digits of year javascript

maskDate(date) {
    // console.log(date);
    var dateVar = new Date(date);
    // console.log("XX/XX/"+ dateVar.getFullYear().toString().substr(-2));
    return "XX/XX/"+ dateVar.getFullYear().toString().substr(-2);
 }