Modern JavaScript function for formatting Date to String yyyy-MM-dd

dateToString.js

function getFormattedDate(d) {
    if(!d){
        d = new Date();
    }
    const transactionDate = [d.getFullYear(), `0${d.getMonth() + 1}`.slice(-2), `0${d.getDate()}`.slice(-2)].join('');
    return transactionDate;
}