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根据具体日期计算是一年的第几周：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script>
// 计算具体日期为当月的第几周
function getWeek(str) {
// 将字符串转为标准时间格式
str = Date.parse(str);
str = new Date(str);
// 先计算出该日期为第几周
let week = Math.ceil(str.getDate()/7);
let month = str.getMonth() + 1;
// 判断这个月前7天是周几，如果不是周一，则计入上个月
if (str.getDate() < 7) {
if (str.getDay() !== 1) {
week = 5;
month = str.getMonth();
}
}
console.log(`${month}-${week}`);
}
console.log(getWeek('2017-01-01'));
</script>
</body>
</html>
根据具体日期计算是当月的第几周：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script>
const year = String(new Date(Date.parse(date)).getFullYear());
console.log('year:', year);
console.log('date:', new Date(year));
const week = (((new Date(date)) - (new Date(year))) / (24 * 60 * 60 * 7 * 1000) | 0) + 1;
console.log('week', week);
</script>
</body>
</html>