微信小程序日期转换、比较、加减

直接上干货：

在utils目录下新建一个dateUtil.js,代码如下：（在需要用的地方引入这个js，调用相关方法传入对应参数就可以使用了）

该工具脚本，实用性很高，通用于各类前端项目，熟悉后亦可以自由扩展，使用中发现问题还请道友留言提示下，本人会同步更新：

//日期转时间戳
function getUnixTime(dateStr){
    var newstr = dateStr.replace(/-/g,'/'); 
    var date =  new Date(newstr); 
    var time_str = date.getTime().toString();
    return time_str.substr(0, 10);
}

//时间戳转日期,falg:true表示只要年月日,part: year month date
function toDate(number,flag,part) {
  var n = number;
  var date = new Date(parseInt(n) * 1000);
  var y = date.getFullYear();
  var m = date.getMonth() + 1;
  m = m < 10 ? ('0' + m) : m;
  var d = date.getDate();
  d = d < 10 ? ('0' + d) : d;
  var h = date.getHours();
  h = h < 10 ? ('0' + h) : h;
  var minute = date.getMinutes();
  var second = date.getSeconds();
  minute = minute < 10 ? ('0' + minute) : minute;
  second = second < 10 ? ('0' + second) : second;
  if(flag){
      if(part == "year"){
          return y;
      }else if(part == "month"){
          return m;
      }else if(part == "date"){
          return n;
      }
      return y + '-' + m + '-' + d;
  }
  return y + '-' + m + '-' + d + ' ' + h + ':' + minute+':' + second;
}

//判断两个日期时间戳相差多少天,参数为时间戳
function dateCompare(dateTimeStamp1,dateTimeStamp2){
    var dayNum = 0;
    if(dateTimeStamp1 > dateTimeStamp2){
        dayNum = Math.floor((dateTimeStamp1 - dateTimeStamp2) / 86400);
    }else{
        dayNum = Math.floor((dateTimeStamp2 - dateTimeStamp1) / 86400);
    }
    return dayNum;
}

//判断过去某个时间点到当前时间是否达到多少天,可以用来定期清理缓存
function datePassDays(dateTimeStamp,days){
    var now = getUnixTime(formatDateThis(new Date()));
    var diffValue = now - dateTimeStamp;
    var limitTime = days * 86400;
    if(diffValue >= limitTime){
        return true;
    }
    return false;
}

//当前日期加减天数,falg:true表示只要年月日
function mathChangeDate(date,method,days,flag){
  //method:'+' || '-'
  //ios不解析带'-'的日期格式，要转成'/'，不然Nan，切记
  var dateVal = date.replace(/-/g, '/');
  var timestamp = Date.parse(dateVal);
  if(method == '+'){
    timestamp = timestamp / 1000 + 24 * 60 * 60 * days;
  } else if (method == '-'){
    timestamp = timestamp / 1000 - 24 * 60 * 60 * days;
  }
  return toDate(timestamp,flag);
}

//时间戳转换具体时间描述(传入数值型时间戳)
function getDateDiff(dateTimeStamp) {
  var result = '';
  var minute = 1 * 60;
  var hour = minute * 60;
  var day = hour * 24;
  var halfamonth = day * 15;
  var month = day * 30;
  var now = getUnixTime(formatDateThis(new Date()));//有些特殊 不能使用 new Date()
  var diffValue = now - dateTimeStamp;
  if (diffValue < 0) { return; }
  var monthC = diffValue / month;
  var weekC = diffValue / (7 * day);
  var dayC = diffValue / day;
  var hourC = diffValue / hour;
  var minC = diffValue / minute;
  
  if (monthC >= 1) {
    result = "" + parseInt(monthC) + "月前";
  }
  else if (weekC >= 1) {
    result = "" + parseInt(weekC) + "周前";
  }
  else if (dayC >= 1) {
    result = "" + parseInt(dayC) + "天前";
  }
  else if (hourC >= 1) {
    result = "" + parseInt(hourC) + "小时前";
  }
  else if (minC >= 1) {
    result = "" + parseInt(minC) + "分钟前";
  } else
    result = "刚刚";
  return result;
};

//获取当前年份，月份， 例： getCurrentTime(new Date(),"year")
const getCurrentTime = (date,method) => {
    if(method == "year"){
        return date.getFullYear();
    }else if(method == "month"){
        return date.getMonth() + 1;
    }
    return date;
}

//获取当前服务器时间,参数直接用 new Date() 就可以了
const formatDateThis = date => {
  const year = date.getFullYear();
  const month = date.getMonth() + 1;
  const day = date.getDate();
  const hour = date.getHours();
  const minute = date.getMinutes();
  const second = date.getSeconds();
  return [year, month, day].map(formatNumber).join('-') +' '+ [hour, minute, second].map(formatNumber).join(':');
}

const formatTime = date => {
  const year = date.getFullYear();
  const month = date.getMonth() + 1;
  const day = date.getDate();
  return [year, month, day].map(formatNumber).join('-');
}
const formatTimes = time => {
  const hour = time.getHours();
  const minute = time.getMinutes();
  const second = time.getSeconds();
  return [hour, minute,second].map(formatNumber).join(':');
}
//补0
const formatNumber = n => {
  n = n.toString();
  return n[1] ? n : '0' + n;
}

//比较两个时间大小(格式参考yyyy-mm-dd hh:mm:ss)
function compareTime(startTime,endTime){
  //结束时间大于开始时间就是true  ， 反之则为 false
  var sn = getUnixTime(startTime) * 1;
  var en = getUnixTime(endTime) * 1;
  if(en > sn){
    return true;
  }
  return false;
}

module.exports = {
  dateCompare:dateCompare,
  getCurrentTime:getCurrentTime,
  getUnixTime:getUnixTime,
  formatDateThis:formatDateThis,
  formatTime: formatTime,
  formatTimes: formatTimes,
  toDate: toDate,
  getDateDiff: getDateDiff,
  mathChangeDate: mathChangeDate,
  compareTime: compareTime,
  datePassDays:datePassDays
}