JS实现年月日

function clock(){
	//实例化当前的时间
	let time = new Date();

	let year = time.getFullYear(),
	month = time.getMonth() + 1,
	day = time.getDate(),
	week = toWeek(time.getDay()),

	hour = time.getHours(),
	min = time.getMinutes(),
	s = time.getSeconds(),
	ms = time.getMilliseconds();

	var retTime = `今天是${year}年${month}月${day}日${week}${hour}时${min}分${s}秒${ms}毫秒`;
	return retTime;
}

function toWeek(week){
	let resWeek = '';
	switch(week){
		case 0:
			resWeek = '日';
		case 1:
			resWeek = '一';
		case 2:
			resWeek = '二';
		case 3:
			resWeek = '三';
		case 4:
			resWeek = '四';
		case 5:
			resWeek = '五';
		case 6:
			resWeek = '六';
	}
	return '星期' + resWeek;
}
console.log(clock());