工作中，经常会需要处理时间！刚开始的时候是使用moment插件，非常强大的一款插件，能够满足工作需求。但是，随着项目的不断扩展，就需要对项目进行一些“瘦身”，基于“杀鸡焉用牛刀”的想法，就自己动手写了一些帮助函数，目前基本能够满足平时工作的需要。
先来看看写的代码的运行效果
DateUTC，用于生成一个Date对象
image.png可能大家会比较奇怪，已经有new Date()方法，为什么还要写一个用法一直的DateUTC方法，来看下面的
image.png
new Date(‘2018-04-01’)得到的时间是早上8点而不是0点，这是因为本地时间和格林威治时间有一个时间差。getTimezoneOffset返回时间差。所以用一个函数DateUTC来对Date做了一层封装
function DateUTC (date) {
let isDate = (typeof date === 'object') && (date instanceof Date)
if (isDate) return date
let localDate
try {
localDate = date === undefined ? new Date() : new Date(date)
} catch (e) {
console.error(e)
}
if (date && /^\d{4}(-\d{2}){0,2}$/.test(date)) {
let timeZoneOffset = localDate.getTimezoneOffset()
let utcTimeStamp = localDate.getTime() + timeZoneOffset * 60 * 1000
return new Date(utcTimeStamp)
}
return localDate
}
工作中，我们可能经常会有这样子的场景，比如在选择时间段的时候，需要取今后的某个时间段。比如，判断两个日期的时间差，以及以固定的格式展示时间等等。个人手写了以下一些代码，运行结果如图
image.png
image.png
最后一个dateSpec（好吧，我承认方法名不太好）方法，是集合以上代码的功能。包括格式化，计算时间差值，获取某个日期之后（前）的一个时间。运行结果如图
image.png
以下是全部完整的代码
/**
* @param {*} date
* test
* let aa = ['2018', '2018-', '2018-01', '2018-01-', '2018-1', '2018-01-02', '2018-01-2', '2018-1-2', '2018-01-2 6:', '2018-01-2 6:2', '2018-01-2 6:2:2']
* aa.forEach(a => console.log(a, reg.test(a), dateSpec(a, 'yyyy-MM-dd HH:mm:ss')))
*/
function leftPad(item) {
return item.toString().length < 2 ? ('0' + item) : item
}
function getTimeStampUnit (unit) {
switch (unit) {
case 'day':
return 1000 * 3600 * 24
case 'hour':
return 1000 * 3600
case 'minute':
return 1000 * 60
case 'second':
return 1000
break
default:
return 1
}
}
// 用法如Date
function DateUTC (date) {
let isDate = (typeof date === 'object') && (date instanceof Date)
if (isDate) return date
let localDate
try {
localDate = date === undefined ? new Date() : new Date(date)
} catch (e) {
console.error(e)
}
if (date && /^\d{4}(-\d{2}){0,2}$/.test(date)) {
let timeZoneOffset = localDate.getTimezoneOffset()
let utcTimeStamp = localDate.getTime() + timeZoneOffset * 60 * 1000
return new Date(utcTimeStamp)
}
return localDate
}
/**
*
* @param {*} time1 a Date object or Date params
* @param {*} time2 a Date object or Date params
* @param {*} unit can be one of ['year', 'month', 'day', 'hour', 'minute', 'second']
*/
function diff (time1, time2, unit='day') {
let date1 = DateUTC(time1)
let date2 = DateUTC(time2)
if (unit === 'year') {
return date2.getFullYear() - date1.getFullYear()
}
if (unit === 'month') {
return date2.getMonth() - date1.getMonth()
}
let timeStampUnit = getTimeStampUnit(unit)
return parseInt((date2.getTime() - date1.getTime()) / timeStampUnit)
}
/**
*
* @param {*} date a Date object or Date params
* @param {*} diff
* @param {*} unit can be one of ['year', 'month', 'day', 'hour', 'minute', 'second']
* for example: dateFrom('2012-02-29', 12, 'month') // Fri Mar 01 2013 00:00:00 GMT+0800 (CST)
*/
function dateFrom(time, diff, unit='day') {
let date = DateUTC(time)
if (unit === 'year') {
let year = date.getFullYear() + diff
return DateUTC(date.setFullYear(year))
}
if (unit === 'month') {
let month = date.getMonth() + diff
return DateUTC(date.setMonth(month))
}
let timeStampUnit = getTimeStampUnit(date.getTime())
return DateUTC(timeStampUnit + diff * timeStampUnit)
}
function format (date, form = 'yyyy-MM-dd') {
date = DateUTC(date)
if (!form) return date
let year = date.getFullYear()
let month = leftPad(date.getMonth() + 1)
let day = leftPad(date.getDate())
let hours = leftPad(date.getHours())
let minutes = leftPad(date.getMinutes())
let seconds = leftPad(date.getSeconds())
return form.replace('yyyy', year).replace('MM', month).replace('dd', day).replace('HH', hours).replace('mm', minutes).replace('ss', seconds)
}
/**
* use it just like how you new a Date and the second value is the format
* if you don't want to format it, set the form to false
* @param {*} value any params can new a Date
* @param {*} form
* @param {*} UTC
*/
function dateSpec (payload) {
if (payload === undefined) return DateUTC()
if (!payload) {
console.error(`error params, the params is an object lise this { form: 'yyyy-MM-dd', diff: 0, unit: 'day', date: '2018-11-19' }`)
}
let { form = 'yyyy-MM-dd', diff = 0, unit = 'day', date = undefined } = payload
let time = date === undefined ? DateUTC() : DateUTC(date)
diff && (time = dateFrom(time, diff, unit))
return form ? format(time, form) : time
// let rs = year + "-" + month + "-" + day + " " + hours + ":" + minutes + ":" + seconds
}
// test
if (true || __DEV__) {
var arr = ['2018', '2018-', '2018-01', '2018-01-', '2018-1', '2018-01-02', '2018-01-2', '2018-1-2', '2018-01-2 6:', '2018-01-2 6:2', '2018-01-2 6:2:2']
console.log(`\n---dateSpec(date, 'yyyy-MM-dd HH:mm:ss')---\n`)
arr.forEach(a => console.log(`\ndateSpec({date: ${a}, form: 'yyyy-MM-dd HH:mm:ss'}))\n`, a, ': ', dateSpec({date: a, form: 'yyyy-MM-dd HH:mm:ss'})))
console.error('\n----DateUTC，用法和Date一致 ----\n')
console.log(`DateUTC([2016, 7]): `, DateUTC([2016, 7]))
console.log(`DateUTC(): `, DateUTC())
console.log(`DateUTC('2019-5-10'): `, DateUTC())
console.error(`format (date, form = 'yyyy-MM-dd') 格式化时间`)
console.log(`format('2018-1', 'HH:mm:ss yyyy/MM/dd'): `, format('2018-1', 'HH:mm:ss yyyy/MM/dd'))
console.error('\n\n----diff：取两个时间的差值（可以选择按照年、月、日、时、分、秒为单位）----\n\n')
console.log(`\ndiff('2014-10-13', '2018-11-15')\n`, 'diff day', diff('2014-10-13', '2018-11-15'))
console.log(`\ndiff('2014-10-13', '2018-11-15', 'year')\n`, 'diff year', diff('2014-10-13', '2018-11-15', 'year'))
console.log(`\ndiff('2014-10-13', '2018-11-15', 'month')\n`, 'diff month',diff('2014-10-13', '2018-11-15', 'month'))
console.log(`\ndiff('2018-01-02 06:02:00', '2018-01-04 07:22:10', 'hour')\n`, 'diff hour', diff('2018-01-02 06:02:00', '2018-01-04 07:22:10', 'hour'))
console.log(`\ndiff('2018-01-02 06:02:00', '2018-01-04 07:22:10', 'minute')\n`, 'diff minute', diff('2018-01-02 06:02:00', '2018-01-04 07:22:10', 'minute'))
console.log(`\ndiff('2018-01-02 06:02:00', '2018-01-04 07:22:10', 'second')\n`, 'diff second', diff('2018-01-02 06:02:00', '2018-01-04 07:22:10', 'second'))
console.error(`\n\n----dateFrom(time, diff, unit='day') ：取与time间隔diff的时间（可以选择按照年、月、日、时、分、秒为单位）----\n\n`)
console.log(`\ndiff('2014-10-13', '2018-11-15')\n`, 'diff day', diff('2014-10-13', '2018-11-15'))
console.log(`\ndiff('2014-10-13', '2018-11-15', 'year')\n`, 'diff year', diff('2014-10-13', '2018-11-15', 'year'))
console.log(`\ndiff('2014-10-13', '2018-11-15', 'month')\n`, 'diff month',diff('2014-10-13', '2018-11-15', 'month'))
console.log(`\ndiff('2018-01-02 06:02:00', '2018-01-04 07:22:10', 'hour')\n`, 'diff hour', diff('2018-01-02 06:02:00', '2018-01-04 07:22:10', 'hour'))
console.log(`\ndiff('2018-01-02 06:02:00', '2018-01-04 07:22:10', 'minute')\n`, 'diff minute', diff('2018-01-02 06:02:00', '2018-01-04 07:22:10', 'minute'))
console.log(`\ndiff('2018-01-02 06:02:00', '2018-01-04 07:22:10', 'second')\n`, 'diff second', diff('2018-01-02 06:02:00', '2018-01-04 07:22:10', 'second'))
console.error(`\n----dateSpec： ----\n
1. 获取某个时间date, {date: '2019-8-11'}，默认为当天\n
1. 格式化时间, {form: 'yyyy-MM-dd HH:mm:ss'}，默认为yyyy-MM-dd格式\n
1. 获取距离date之前或之后的某个时间(diff: 时间差， unit：单位（可以是年月日时分秒））, {diff: -4, unit: 'hour'}，unit默认为day\n`)
console.log('\ndateSpec()\n', 'today: ', dateSpec())
console.log('\ndateSpec({})\n', 'today: ', dateSpec({}))
console.log(`\ndateSpec({form: 'HH:mm:ss yyyy/MM/dd'})\n`, 'today: ', dateSpec({form: 'HH:mm:ss yyyy/MM/dd'}))
console.log(`\ndateSpec({diff: -3})\n`, 'three days ago: ', dateSpec({diff: -3}))
console.log(`\ndateSpec({diff: 3, unit: 'month'})\n`, 'three month later: ', dateSpec({diff: 3, unit: 'month'}))
console.log(`\ndateSpec({diff: 1, unit: 'year'})\n`, 'one year later: ', dateSpec({diff: 1, unit: 'year'}))
console.log(`\ndateSpec({diff: -1, unit: 'hour', form: 'HH:mm:ss yyyy/MM/dd'})\n`, 'one hour ago: ', dateSpec({diff: -1, unit: 'hour', form: 'HH:mm:ss yyyy/MM/dd'}))
console.log(`\ndateSpec({diff: -20, unit: 'minute', form: 'HH:mm:ss yyyy/MM/dd'})\n`, '20 minute ago: ', dateSpec({diff: -20, unit: 'minute', form: 'HH:mm:ss yyyy/MM/dd'}))
console.log(`\ndateSpec({diff: 100, unit: 'second', form: 'HH:mm:ss yyyy/MM/dd'})\n`, '100 second later: ', dateSpec({diff: 100, unit: 'second', form: 'HH:mm:ss yyyy/MM/dd'}))
}
为了更好的展示输出结果，所以用了一个console.error来分割
以上
