JavaScript 获取当前日期在本月的第几周

function getWeekOfMonth() {
    let date = new Date();
    let firstDay = new Date(date.getFullYear(), date.getMonth(), 1);
    let dayOfWeek = firstDay.getDay(); // 获取第一天是周几
    let spendDay = 1;
    if (dayOfWeek != 0) {
        spendDay = 7 - dayOfWeek + 1;
    }
    firstDay = new Date(date.getFullYear(), date.getMonth(), 1 + spendDay);
    let d = Math.ceil((date.valueOf() - firstDay.valueOf()) / 86400000);
    let result = Math.ceil(d / 7);
    return result + 1;
}

console.log(getWeekOfMonth());