常用方法的封装

一、数组的处理

1、随机获取数组里面的N个对象

   getRandomArrayElements(arr, count) {
      var shuffled = arr.slice(0),
        i = arr.length,
        min = i - count,
        temp,
        index;
      while (i-- > min) {
        index = Math.floor((i + 1) * Math.random());
        temp = shuffled[index];
        shuffled[index] = shuffled[i];
        shuffled[i] = temp;
      }
      return shuffled.slice(min);
    },

一、日期范围类

// 获取 本周 本月 本季度 本年的日期范围

/**
* 日期范围工具类
*/
export default  {
  /***
  * 获得当前时间
  */
  getCurrentDate : function () {
      return new Date();
  },

  /***
  * 获得本周起止时间
  */
getCurrentWeek : function () {
      //起止日期数组
      var startStop = new Array();
      //获取当前时间
      var currentDate = this.getCurrentDate();
      //返回date是一周中的某一天
      var week = currentDate.getDay();
      //返回date是一个月中的某一天
      var month = currentDate.getDate();

      //一天的毫秒数
      var millisecond = 1000 * 60 * 60 * 24;
      //减去的天数
      var minusDay = week != 0 ? week - 1 : 6;
      //alert(minusDay);
      //本周 周一
      var monday = new Date(currentDate.getTime() - (minusDay * millisecond));
      //本周 周日
      var sunday = new Date(monday.getTime() + (6 * millisecond));
      //添加本周时间
      startStop.push(monday.format("yyyy-MM-dd")); //本周起始时间
      //添加本周最后一天时间
      startStop.push(sunday.format("yyyy-MM-dd")); //本周终止时间
      //返回
      return startStop;
  },

  /***
  * 获得本月的起止时间
  */
getCurrentMonth : function () {
      //起止日期数组
      var startStop = new Array();
      //获取当前时间
      var currentDate = this.getCurrentDate();
      //获得当前月份0-11
      var currentMonth = currentDate.getMonth();
      //获得当前年份4位年
      var currentYear = currentDate.getFullYear();
      //求出本月第一天
      var firstDay = new Date(currentYear, currentMonth, 1);


      //当为12月的时候年份需要加1
      //月份需要更新为0 也就是下一年的第一个月
      if (currentMonth == 11) {
          currentYear++;
          currentMonth = 0; //就为
      } else {
          //否则只是月份增加,以便求的下一月的第一天
          currentMonth++;
      }


      //一天的毫秒数
      var millisecond = 1000 * 60 * 60 * 24;
      //下月的第一天
      var nextMonthDayOne = new Date(currentYear, currentMonth, 1);
      //求出上月的最后一天
      var lastDay = new Date(nextMonthDayOne.getTime() - millisecond);

      //添加至数组中返回
      startStop.push(firstDay.format("yyyy-MM-dd"));
      startStop.push(lastDay.format("yyyy-MM-dd"));
      //返回
      return startStop;
  },

  /**
  * 得到本季度开始的月份
  * @param month 需要计算的月份
  ***/
getQuarterSeasonStartMonth : function (month) {
      var quarterMonthStart = 0;
      var spring = 0; //春
      var summer = 3; //夏
      var fall = 6;   //秋
      var winter = 9; //冬
      //月份从0-11
      if (month < 3) {
          return spring;
      }

      if (month < 6) {
          return summer;
      }

      if (month < 9) {
          return fall;
      }

      return winter;
  },

  /**
  * 获得该月的天数
  * @param year年份
  * @param month月份
  * */
getMonthDays: function (year, month) {
      //本月第一天 1-31
      var relativeDate = new Date(year, month, 1);
      //获得当前月份0-11
      var relativeMonth = relativeDate.getMonth();
      //获得当前年份4位年
      var relativeYear = relativeDate.getFullYear();

      //当为12月的时候年份需要加1
      //月份需要更新为0 也就是下一年的第一个月
      if (relativeMonth == 11) {
          relativeYear++;
          relativeMonth = 0;
      } else {
          //否则只是月份增加,以便求的下一月的第一天
          relativeMonth++;
      }
      //一天的毫秒数
      var millisecond = 1000 * 60 * 60 * 24;
      //下月的第一天
      var nextMonthDayOne = new Date(relativeYear, relativeMonth, 1);
      //返回得到上月的最后一天,也就是本月总天数
      return new Date(nextMonthDayOne.getTime() - millisecond).getDate();
  },

  /**
  * 获得本季度的起止日期
  */
getCurrentSeason : function () {
      //起止日期数组
      var startStop = new Array();
      //获取当前时间
      var currentDate = this.getCurrentDate();
      //获得当前月份0-11
      var currentMonth = currentDate.getMonth();
      //获得当前年份4位年
      var currentYear = currentDate.getFullYear();
      //获得本季度开始月份
      var quarterSeasonStartMonth = this.getQuarterSeasonStartMonth(currentMonth);
      //获得本季度结束月份
      var quarterSeasonEndMonth = quarterSeasonStartMonth + 2;

      //获得本季度开始的日期
      var quarterSeasonStartDate = new Date(currentYear, quarterSeasonStartMonth, 1);
      //获得本季度结束的日期
      var quarterSeasonEndDate = new Date(currentYear, quarterSeasonEndMonth, this.getMonthDays(currentYear, quarterSeasonEndMonth));
      //加入数组返回
      startStop.push(quarterSeasonStartDate.format("yyyy-MM-dd"));
      startStop.push(quarterSeasonEndDate.format("yyyy-MM-dd"));
      //返回
      return startStop;
  },

    /**
  * 获得本季度的开始到当前的日期
  */
    getCurrentSeasonToday : function () {
        //起止日期数组
        var startStop = new Array();
        //获取当前时间
        var currentDate = this.getCurrentDate();
        //获得当前月份0-11
        var currentMonth = currentDate.getMonth();
        //获得当前年份4位年
        var currentYear = currentDate.getFullYear();
        //获得本季度开始月份
        var quarterSeasonStartMonth = this.getQuarterSeasonStartMonth(currentMonth);
        //获得本季度结束月份
        var quarterSeasonEndMonth = quarterSeasonStartMonth + 2;

        //获得本季度开始的日期
        var quarterSeasonStartDate = new Date(currentYear, quarterSeasonStartMonth, 1);
        //加入数组返回
        startStop.push(quarterSeasonStartDate.format("yyyy-MM-dd"));
        startStop.push(currentDate.format("yyyy-MM-dd"));
        //返回
        return startStop;
    },
  /***
  * 得到本年的起止日期
  *
  */
getCurrentYear : function () {
      //起止日期数组
      var startStop = new Array();
      //获取当前时间
      var currentDate = this.getCurrentDate();
      //获得当前年份4位年
      var currentYear = currentDate.getFullYear();

      //本年第一天
      var currentYearFirstDate = new Date(currentYear, 0, 1);
      //本年最后一天
      var currentYearLastDate = new Date(currentYear, 11, 31);
      //添加至数组
      startStop.push(currentYearFirstDate.format("yyyy-MM-dd"));
      startStop.push(currentYearLastDate.format("yyyy-MM-dd"));
      //返回
      return startStop;
  },

  /**
  * 返回上一个月的第一天Date类型
  * @param year 年
  * @param month 月
  **/
getPriorMonthFirstDay: function (year, month) {
      //年份为0代表,是本年的第一月,所以不能减
      if (month == 0) {
          month = 11; //月份为上年的最后月份
          year--; //年份减1
          return new Date(year, month, 1);
      }
      //否则,只减去月份
      month--;
      return new Date(year, month, 1); ;
  },

  /**
  * 获得上一月的起止日期
  * ***/
getPreviousMonth : function () {
      //起止日期数组
      var startStop = new Array();
      //获取当前时间
      var currentDate = this.getCurrentDate();
      //获得当前月份0-11
      var currentMonth = currentDate.getMonth();
      //获得当前年份4位年
      var currentYear = currentDate.getFullYear();
      //获得上一个月的第一天
      var priorMonthFirstDay = this.getPriorMonthFirstDay(currentYear, currentMonth);
      //获得上一月的最后一天
      var priorMonthLastDay = new Date(priorMonthFirstDay.getFullYear(), priorMonthFirstDay.getMonth(), this.getMonthDays(priorMonthFirstDay.getFullYear(), priorMonthFirstDay.getMonth()));
      //添加至数组
      startStop.push(priorMonthFirstDay.format("yyyy-MM-dd"));
      startStop.push(priorMonthLastDay.format("yyyy-MM-dd"));
      //返回
      return startStop;
  },


  /**
  * 获得上一周的起止日期
  * **/
getPreviousWeek : function () {
      //起止日期数组
      var startStop = new Array();
      //获取当前时间
      var currentDate = this.getCurrentDate();
      //返回date是一周中的某一天
      var week = currentDate.getDay();
      //返回date是一个月中的某一天
      var month = currentDate.getDate();
      //一天的毫秒数
      var millisecond = 1000 * 60 * 60 * 24;
      //减去的天数
      var minusDay = week != 0 ? week - 1 : 6;
      //获得当前周的第一天
      var currentWeekDayOne = new Date(currentDate.getTime() - (millisecond * minusDay));
      //上周最后一天即本周开始的前一天
      var priorWeekLastDay = new Date(currentWeekDayOne.getTime() - millisecond);
      //上周的第一天
      var priorWeekFirstDay = new Date(priorWeekLastDay.getTime() - (millisecond * 6));

      //添加至数组
      startStop.push(priorWeekFirstDay.format("yyyy-MM-dd"));
      startStop.push(priorWeekLastDay.format("yyyy-MM-dd"));

      return startStop;
  },

  /**
  * 得到上季度的起始日期
  * year 这个年应该是运算后得到的当前本季度的年份
  * month 这个应该是运算后得到的当前季度的开始月份
  * */
getPriorSeasonFirstDay: function (year, month) {
      var quarterMonthStart = 0;
      var spring = 0; //春
      var summer = 3; //夏
      var fall = 6;   //秋
      var winter = 9; //冬
      //月份从0-11
      switch (month) {//季度的其实月份
          case spring:
              //如果是第一季度则应该到去年的冬季
              year--;
              month = winter;
              break;
          case summer:
              month = spring;
              break;
          case fall:
              month = summer;
              break;
          case winter:
              month = fall;
              break;

      }

      return new Date(year, month, 1);
  },

  /**
  * 得到上季度的起止日期
  * **/
getPreviousSeason : function () {
      //起止日期数组
      var startStop = new Array();
      //获取当前时间
      var currentDate = this.getCurrentDate();
      //获得当前月份0-11
      var currentMonth = currentDate.getMonth();
      //获得当前年份4位年
      var currentYear = currentDate.getFullYear();
      //上季度的第一天
      var priorSeasonFirstDay = this.getPriorSeasonFirstDay(currentYear, currentMonth);
      //上季度的最后一天
      var priorSeasonLastDay = new Date(priorSeasonFirstDay.getFullYear(), priorSeasonFirstDay.getMonth() + 2, this.getMonthDays(priorSeasonFirstDay.getFullYear(), priorSeasonFirstDay.getMonth() + 2));
      //添加至数组
      startStop.push(priorSeasonFirstDay.format("yyyy-MM-dd"));
      startStop.push(priorSeasonLastDay.format("yyyy-MM-dd"));
      return startStop;
  },

  /**
  * 得到去年的起止日期
  * **/
getPreviousYear : function () {
      //起止日期数组
      var startStop = new Array();
      //获取当前时间
      var currentDate = this.getCurrentDate();
      //获得当前年份4位年
      var currentYear = currentDate.getFullYear();
      currentYear--;
      var priorYearFirstDay = new Date(currentYear, 0, 1);
      var priorYearLastDay = new Date(currentYear, 11, 1);
      //添加至数组
      startStop.push(priorYearFirstDay.format("yyyy-MM-dd"));
      startStop.push(priorYearLastDay.format("yyyy-MM-dd"));
      return startStop;
  },
// 获取这是第几周
getYearWeek: function(time) {
    var totalDays = 0;
    let now = new Date(time);
    let years = now.getYear()
    if (years < 1000)
     years += 1900
    var days = new Array(12);
    days[0] = 31;
    days[2] = 31;
    days[3] = 30;
    days[4] = 31;
    days[5] = 30;
    days[6] = 31;
    days[7] = 31;
    days[8] = 30;
    days[9] = 31;
    days[10] = 30;
    days[11] = 31;
    //判断是否为闰年，针对2月的天数进行计算
    if (Math.round(now.getYear() / 4) == now.getYear() / 4) {
     days[1] = 29
    } else {
     days[1] = 28
    }
    if (now.getMonth() == 0) {
     totalDays = totalDays + now.getDate();
    } else {
     var curMonth = now.getMonth();
     for (var count = 1; count <= curMonth; count++) {
       totalDays = totalDays + days[count - 1];
     }
     totalDays = totalDays + now.getDate();
    }
    //得到第几周
    var week = Math.round(totalDays / 7);
    return week;
  },
  /***
    * 根据指定时间获得本周起止时间
    * flag为-1 则周一为一周的开始时间 为0则星期天为一周的开始时间
    */
  getCurrentWeekByAppointTime : function (time, flag) {
        //起止日期数组
        var startStop = new Array();
        //获取当前时间
        var currentDate = time;
        //返回date是一周中的某一天
        var week = currentDate.getDay();
        //返回date是一个月中的某一天
        var month = currentDate.getDate();

        //一天的毫秒数
        var millisecond = 1000 * 60 * 60 * 24;
        //减去的天数
        var minusDay = week != 0 ? week + flag : 6;
        //alert(minusDay);
        //本周 周一
        var monday = new Date(currentDate.getTime() - (minusDay * millisecond));
        //本周 周日
        var sunday = new Date(monday.getTime() + (6 * millisecond));
        //添加本周时间
        startStop.push(monday.format("yyyy-MM-dd")); //本周起始时间
        //添加本周最后一天时间
        startStop.push(sunday.format("yyyy-MM-dd")); //本周终止时间
        //返回
        return startStop;
    },
}

Date.prototype.format = function(fmt) {
  var o = {
      "M+" : this.getMonth()+1, //月份
      "d+" : this.getDate(), //日
      "h+" : this.getHours(), //小时
      "m+" : this.getMinutes(), //分
      "s+" : this.getSeconds(), //秒
      "q+" : Math.floor((this.getMonth()+3)/3), //季度
      "S" : this.getMilliseconds() //毫秒
  }
  if(/(y+)/.test(fmt)) {
      fmt=fmt.replace(RegExp.$1, (this.getFullYear()+"").substr(4 - RegExp.$1.length));
  }
  for(var k in o) {
      if(new RegExp("("+ k +")").test(fmt)){
          fmt = fmt.replace(RegExp.$1, (RegExp.$1.length==1) ? (o[k]) : (("00"+ o[k]).substr((""+ o[k]).length)));
      }
  }
  return fmt;
}
 /**
  * 获取某一天的日期
  * n:指定天数 列：0：当天   6：六天以后    -6:6天以前
  * **/
getRecentDay : function (n:any) {
    let day = moment(new Date())
      .subtract(n, "days")
      .format("YYYY-MM-DD");
    return day;
  }
}