时间的格式的封装

第三章

在开发中,我们经常会遇到对于时间的进行封装

这个我不得不提一下微信小程序中自带封装, 不得不说, 写的很好, 值得我学习

工整, 美观, (或许这就是代码之美吧)

• 格式化:

const formatTime = date => {
    date = new Date(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 formatNumber = n => {
    n = n.toString()
    return n[1] ? n : '0' + n
}

$感觉这个更加是无敌$感觉这个更加是无敌
与上面这个效果是一样的

let d = new Date();
d.toJSON().substr(0,10)+' '+d.toTimeString().substr(0,8)

当然除了substr()字符串方法, 也有substring(), 与slice(), 方法, (slice 与在字符串与数组中均可使用)

• 另一种方法

join(’-’), 既可以用在数组中, 也可以用在字符串中

const formatDate = date => {
    var d = new Date(date),
        month = '' + (d.getMonth() + 1),
        day = '' + d.getDate(),
        year = d.getFullYear();

    if (month.length < 2) month = '0' + month; //通过字符串的长度判断
    if (day.length < 2) day = '0' + day;

    return [year, month, day].join('-');
}

• 倒计时:

// 倒计时处理
const getOverTime = time => {
    let a = new Date(time).getTime();
    let c = a - Date.now();
    if (c <= 0) {
        return false
    }
    let days = Math.floor(c / (24 * 3600 * 1000));
    let leave1 = c % (24 * 3600 * 1000); //计算天数后剩余的毫秒数
    let hours = Math.floor(leave1 / (3600 * 1000));
    let leave2 = leave1 % (3600 * 1000); //计算小时数后剩余的毫秒数
    let minutes = Math.floor(leave2 / (60 * 1000));
    let leave3 = leave2 % (60 * 1000); //计算分钟数后剩余的毫秒数
    let seconds = Math.round(leave3 / 1000);
    return days + "天" + hours + "小时" + minutes + "分钟" + seconds + "秒";
}

• 判断时间
  这个写的不是很好, 应该可以理由高阶函数在对这个进行简化

function getDateDiff(dateTimeStamp) {
  const minute = 1000 * 60;
  const hour = minute * 60;
  const day = hour * 24;
  const month = day * 30;
  const year = day * 365;
  const now = new Date().getTime();
  const diffValue = now - dateTimeStamp;
  if(diffValue < 0){
   
      return '数据出错';
  }

  const yearC = diffValue / year;
  const monthC = diffValue / month;
  const weekC = diffValue / (7 * day);
  const dayC = diffValue / day;
  const hourC = diffValue / hour;
  const minC = diffValue / minute;
  let result = '';



  if(yearC >= 1){
      result = parseInt(yearC) + '年以前';
  }else if(monthC >= 1){
      result = parseInt(monthC) + '个月前';
  }else if(weekC >= 1){
      result = parseInt(weekC) + '星期前';
  }else if(dayC >= 1){
      result = parseInt(dayC) + '天前';
  }else if(hourC >= 1){
      result = parseInt(hourC) + '小时前';
  }else if(minC >= 5){
      result = parseInt(minC) + '分钟前';
  }else{
      result = '刚刚发表';
  }
  return result;
}