安装:

NPM:

npm install dayjs --save

import dayjs from 'dayjs'
// 或者 CommonJS
// var dayjs = require('dayjs');
dayjs().format();  //2020-01-06T10:15:01+08:00

CDN:

<!-- 最新的压缩后的 JavaScript 文件 -->
<script src="https://unpkg.com/dayjs"></script>
<script>
  dayjs().format();
</script>

实现

var dayjs = require('dayjs');

//当前年的最开始
// console.log( dayjs().startOf('year').$d.valueOf());
let yearStar = dayjs().startOf('year').$d.valueOf();

//当前月的最开始
// console.log(dayjs().startOf('month').$d.valueOf());
let monthStar = dayjs().startOf('month').$d.valueOf();

//当前周的最开始
// console.log(dayjs().startOf('week').$d.valueOf());
let weekStar = dayjs().startOf('week').$d.valueOf();

//当前天的最开始
// console.log(dayjs().startOf('day').$d.valueOf());
let todayStar = dayjs().startOf('day').$d.valueOf();
//昨天的最开始
let yestodayStar = dayjs().startOf('day').$d.valueOf() - 1000*60*60*24;

let currenttime;



let ss = 1577145600000;

//超出今年的年份
if(ss < yearStar){
    //本身所在的年份 let ss = 1525492800000;
    console.log('本身所在的年份');
    let month = dayjs(ss).month()+1
    let date = dayjs(ss).date()

    month > 10 ?  month = month :   month = '0'+ month
    date > 10 ?  date = date :   date = '0'+ date
    
    currenttime = `${dayjs(ss).year()}-${month}-${date}`
}

//在今年不在本月中
if(ss > yearStar && ss < monthStar ){
    //当前年的日期 let ss = 1571760000000;
    console.log('当前年的日期');

    let month = dayjs(ss).month()+1
    let date = dayjs(ss).date()

    month > 10 ?  month = month :   month = '0'+ month
    date > 10 ?  date = date :   date = '0'+ date
    currenttime = `${dayjs(ss).year()}-${month}-${date}`
    
}

//在本月不在本周
if(ss > monthStar && ss < weekStar ){
    //当前月的日期 let ss = 1575302400000;
    console.log('当前月的日期');
    let month = dayjs(ss).month()+1
    let date = dayjs(ss).date()

    month > 10 ?  month = month :   month = '0'+ month
    date > 10 ?  date = date :   date = '0'+ date 

    currenttime = `${month}-${date}`
}

//在本周不在昨天
if(ss > weekStar && ss < yestodayStar){
    //周几  let ss = 1576987200000;
    console.log('周几');
    let weekObj = {0:'日',1:'一',2:'二',3:'三',4:'四',5:'五',6:'六'};
    let week = dayjs(ss).day()
    let weekValue = weekObj[week];
    
    let hour = dayjs(ss).hour()
    let minute = dayjs(ss).minute()
    hour > 10 ?  hour = hour :   hour = '0'+ hour
    minute > 10 ?  minute = minute :   minute = '0'+ minute 

    currenttime = `周${weekValue}-${hour}:${minute}` 
}

//昨天的
if( ss > yestodayStar &&  ss < todayStar) {
    //昨天 let ss = 1577073600000;
    console.log('昨天');

     
    let hour = dayjs(ss).hour()
    let minute = dayjs(ss).minute()
    hour > 10 ?  hour = hour :   hour = '0'+ hour
    minute > 10 ?  minute = minute :   minute = '0'+ minute 

    currenttime = `昨天-${hour}:${minute}`
    
    
}

//当天的
if(ss > todayStar){
    //时 + 分 let ss = 1577145600000;
    console.log('今天');
    
    let hour = dayjs(ss).hour()
    let minute = dayjs(ss).minute()
    hour > 10 ?  hour = hour :   hour = '0'+ hour
    minute > 10 ?  minute = minute :   minute = '0'+ minute 

    currenttime = `${hour}:${minute}`
}


console.log(currenttime);

//十位时间戳转换日期格式
export const TimeStamp = (shijianchuo) => {
  function add0(m) { return m < 10 ? '0' + m : m }
  let time = new Date(shijianchuo * 1000);
  let y = time.getFullYear();
  let m = time.getMonth() + 1;
  let d = time.getDate();
  let h = time.getHours();
  let mm = time.getMinutes();
  let s = time.getSeconds();
  return y + '-' + add0(m) + '-' + add0(d) + ' ' + add0(h) + ':' + add0(mm) + ':' + add0(s);
}

//时间差值转换为时间格式(倒计时,十位时间戳)
export const timeDate = (shijianchuo) => {
  function add0(m) { return m < 10 ? '0' + m : m }
  var year = add0(Math.floor(shijianchuo / 86400 / 365));
  shijianchuo = shijianchuo % (86400 * 365);
  var month = add0(Math.floor(shijianchuo / 86400 / 30));
  shijianchuo = shijianchuo % (86400 * 30);
  var day = add0(Math.floor(shijianchuo / 86400));
  shijianchuo = shijianchuo % 86400;
  var hour = add0(Math.floor(shijianchuo / 3600));
  shijianchuo = shijianchuo % 3600;
  var minute = add0(Math.floor(shijianchuo / 60));
  shijianchuo = shijianchuo % 60;
  var second = add0(shijianchuo);
  let obj = {}
  return obj = {
    year,
    month,
    day,
    hour,
    minute,
    second,
  }
}

//保留两位小数
export const GetFloat= (x) => {
  if (x != '.'){
    var f = Math.round(x * 100) / 100;
    var s = f.toString();
    var rs = s.indexOf('.');
    if (rs <= 0) {
      rs = s.length;
      s += '.';
    }
    while (s.length <= rs + 2) {
      s += '0';
    }
    return s;
  }else{
    return '0.00';
  }
}
///或者使用
number.toFixed(2);

//异或加密
export function Exclusive(value) {
  let pass = 1;
  let x = ff(pass, value)
  function ff(pass, value) {
    let last = ''
    for (let i = 0; i < value.length; i++) {
      let text2 = ''
      text2 = value.charCodeAt(i) ^ pass
      last += String.fromCharCode(text2)
    }
    return last
  }
  return x
}