JS日期转化指定格式，获取月/周日期区间

该篇文章主要用于收录JS对Date类型的处理，包括但不限于转化指定格式、获取各种月/周的日期区间等等

获取一年中第一个星期一

function getFirstMondayOfYear(year) {let date = new Date(year, 0, 1) // 1月1日while (date.getDay() !== 1) { // 找到第一个星期一date.setDate(date.getDate() + 1)}return date
}

获取一年中最后一个星期一

function getLastMondayOfYear(year) {let date = new Date(year, 11, 31) // 12月31日while (date.getDay() !== 1) { // 找到第一个星期一date.setDate(date.getDate() - 1)}return date
}

获取当天所在周的周一与周日对应的日期区间

function getCurrentWeekRange(today) {let dayOfWeek = today.getDay()let startOfWeek = new Date(today)startOfWeek.setDate(today.getDate() - (dayOfWeek === 0 ? 6 : dayOfWeek - 1))let endOfWeek = new Date(today)endOfWeek.setDate(startOfWeek.getDate() + 6)return [startOfWeek, endOfWeek]
}

获取当天所在月的月初与月末对应的日期区间

function getCurrentMonthRange(today) {let firstDayOfMonth = new Date(today.getFullYear(), today.getMonth(), 1)let lastDayOfMonth = new Date(today.getFullYear(), today.getMonth() + 1, 0)return [firstDayOfMonth, lastDayOfMonth]
}

获取一年中的周数

function getWeeksInYear(year) {let firstMonday = getFirstMondayOfYear(year)let lastMonday = getLastMondayOfYear(year)let weeks = Math.floor((lastMonday - firstMonday) / 86400000 / 7) + 1 // 计算周数return weeks
}

获取某年某周的日期区间

function getWeekRange(year, weekNumber) {let firstMonday = getFirstMondayOfYear(year)let start = new Date(firstMonday)start.setDate(start.getDate() + 7 * (weekNumber - 1))let end = new Date(start)end.setDate(end.getDate() + 6)return [start, end]
}

转换日期类型为指定格式

/*** @Description: 转换日期类型为指定格式* @param date: String | Date, 日期（String需支持转换Date）* @param format: String, 格式示例（以一年中的一月一日作为示例）* @return String（目前支持年月日/年月/月日）**/
function getFormatDate(date, format) {const currentDate = new Date(date)let formatDate = ''let isYear = true // 示例是否包含年份let formatArray = [] // 拆解示例文本中的各部分let part = ''for(let i of format) {if(!isNaN(i)) part += ielse {formatArray.push(part)formatArray.push(i)part = ''}}if(part) formatArray.push(part)formatArray.forEach((item, index) => {let partText = ''// 第一个数字可能为年份或者月份if(index === 0) {if(item.length > 2) partText = currentDate.getFullYear()if(item.length === 2) {partText = (currentDate.getMonth() + 1).toString().padStart(2, '0')isYear = false}if(item.length < 2) {partText = currentDate.getMonth() + 1isYear = false}}// 第二个数字可能为月份或天数else if(index === 2) {if(item.length === 2 && isYear) partText = (currentDate.getMonth() + 1).toString().padStart(2, '0')if(item.length < 2 && isYear) partText = currentDate.getMonth() + 1if(item.length === 2 && !isYear) partText = currentDate.getDate().toString().padStart(2, '0')if(item.length < 2 && !isYear) partText = currentDate.getDate()}// 第三个数字为天数else if(index === 4) {if(item.length === 2) partText = currentDate.getDate().toString().padStart(2, '0')if(item.length < 2) partText = currentDate.getDate()}else partText = itemformatDate += partText})return formatDate
}

获取某一年中每一周的日期区间的数组集合

/*** @Description: 获取某一年中每一周的日期区间的数组集合* @param year: number, 年份* @return Array**/
function getWeeks(year) {let weeksInYear = getWeeksInYear(year) // 计算一年中的周数let data = []while(weeksInYear !== 0) {let weekRange = getWeekRange(year, weeksInYear)let start = getFormatDate(weekRange.start, '01-01')let end = getFormatDate(weekRange.end, '01-01')let string = start + '~' + end + '（第' + weeksInYear + '周）'weeksInYear--data.unshift(string)}return data
}

判断日期是否为未来的日期

function isFutureDate(date) {let today = new Date()let nowTime = today.getTime()let dateTime = date.getTime()return dateTime > nowTime
}