处理时间对象的公共方法

function initDate(date, format = '-') {
    const year = date.getFullYear();
    let month = date.getMonth() + 1;
    if (month < 10) {
        month = '0' + month;
    }
    let day = date.getDate();
    if (day) {
        day = '0' + day;
    }
    return year + format + month + format + day;
}
const a = initDate(new Date(), '/');