js中当前时间的前一个月

function getPreviousMonth() {
    const currentDate = new Date();
    let year = currentDate.getFullYear();
    let month = currentDate.getMonth(); // 0-11

    if (month === 0) {
        month = 11;
        year -= 1;
    } else {
        month -= 1;
    }

    const previousMonthDate = new Date(year, month, 1);
    return previousMonthDate;
}

console.log(getPreviousMonth());

function getPreviousMonthLastDay() {
    const currentDate = new Date();
    let year = currentDate.getFullYear();
    let month = currentDate.getMonth();

    if (month === 0) {
        month = 11;
        year -= 1;
    } else {
        month -= 1;
    }

    const previousMonthLastDay = new Date(year, month + 1, 0);
    return previousMonthLastDay;
}

console.log(getPreviousMonthLastDay());