请教一个需求js怎么判断时间戳是否属于同一天

Question

在addHisList中if应该怎么按天去划分判断，最终渲染出下图的效果，请教一下各位有什么思路不？谢谢

function addHisList(obj) {
    var dom = '';
    if(...){
        dom += '<div>' + changeTime(obj.date,true) + '</div>';//日期
    }
    
    dom += '<div>' + obj.SName + '</div>';
    dom += '<div>' + obj.content + '</div>';
    return dom;
}

//渲染列表的地方
for (...) {
    changelookDom += addHisList(history[i])
}

//数据源
history = [
    {"type":"text","date":1592889320877,"SName":"xxx","content":"1"},
    {"type":"text","date":1592889320877,"SName":"xxx","content":"2"},
    {"type":"text","date":1592889320877,"SName":"xxx","content":"3"}, 
    {"type":"text","date":1592889320877,"SName":"xxx","content":"4"}
]

Answer 1

首先，你需要保证你的时间信息默认已经是按顺序添加的，这样才能有下面的处理
其次需要一个上层的静态变量或者全局变量存储上次的时间

大致的逻辑(不包含上层lastDateStr变量)：

function getDateStr(Mdate){
  let mdate=new Date(Mdate);
  return ( ( mdate.toLocaleDateString() ).replace(/\//g,"-") );
}
function addHisList(obj) {
    var dom = '';
    cDateStr= getDateStr( obj.date)
    if(cDateStr!=lastDateStr){
        dom += '<div>' + changeTime(obj.date,true) + '</div>';//日期
        lastDateStr=cDateStr;
    }
    
    dom += '<div>' + obj.SName + '</div>';
    dom += '<div>' + obj.content + '</div>';
    return dom;
}

Answer 2

思路就是把history数组处理成一个相同日期是在同一个数组成员内，再调整一下 addHisList 函数就可以
demo 链接：https://codepen.io/liangxh052...

function handleHistory(history) {
  const arr = history.map(item => {
    return {
        date: dateFormat(item.date, 'YYYY-MM-DD'),
        list: [
            {
                SName: item.SName,
                content: item.content
            }
        ]
    }
  });
  let result = [];
  arr.forEach(item => {
    if (result.some(every => every.date === item.date)) {
        result.forEach(_ => {
          if(_.date === item.date) {
            _.list = _.list.concat(item.list)
          }
        })
    } else {
        result.push(item)
    }
})
  return result;
}

const history = [
    {"type":"text","date":1592889320877,"SName":"xxx","content":"1"},
    {"type":"text","date":1592889320877,"SName":"xxx","content":"2"},
    {"type":"text","date":1592889320877,"SName":"xxx","content":"3"}, 
    {"type":"text","date":1592889320877,"SName":"xxx","content":"4"},
    {"type":"text","date":1592981108862,"SName":"xxx","content":"4"}
]

console.log(handleHistory(history))


function dateFormat (date, format, en) {
    let self = new Date(date);
    let fmt = format || 'YYYY-MM-DD hh:mm:ss';
    let o = {
        'M+': self.getMonth() + 1,
        'D+': self.getDate(),
        'h+': self.getHours(),
        'H+': self.getHours() % 12 === 0 ? 12 : self.getHours() % 12,
        'N': self.getHours() >= 12 ? (en ? 'PM' : '\u4e0b') : (en ? 'AM' : '\u4e0a'),
        'm+': self.getMinutes(),
        's+': self.getSeconds(),
        'q+': Math.floor((self.getMonth() + 3) / 3),
        'S': self.getMilliseconds()
    };
    if (/(Y+)/.test(fmt)) {
        fmt = fmt.replace(RegExp.$1, (self.getFullYear() + '').substr(4 - RegExp.$1.length));
    }
    for (let 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)));
        }
    }
    let week = ['\u65e5', '\u4e00', '\u4e8c', '\u4e09', '\u56db', '\u4e94', '\u516d'];
    let weekEn = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
    if (/(d+)/.test(fmt)) {
        if (en) {
            fmt = fmt.replace(RegExp.$1, (RegExp.$1.length > 1) ? weekEn[self.getDay()].substr(0, 3) : weekEn[self.getDay()]);
        } else {
            fmt = fmt.replace(RegExp.$1, ((RegExp.$1.length > 1) ? (RegExp.$1.length > 2 ? '\u661f\u671f' : '\u5468') : '') + week[self.getDay()]);
        }
    }
    return fmt;
};

Answer 3

简单点就 看年月日都相等来划分呗，写个format函数转为年月日串，对比串是否相等。

Answer 4

// 假设时间是：2020-06-24 12:00:00
// 假设已经有转格式的方法，或者你用 momentJS 吧
// 准备的方法：比较从今天开始到结束的分秒时
const DATETIME = '2020-06-24 12:00:00';
const today = new Date().format('YYYY-MM-DD 00:00:00');
const todayStart = new Date(today).getTime();
const dateTime = new Date(DATETIME).getTime();

return dateTime > todayStart && dateTime < todayStart + 24 * 60 * 60 * 1000

Answer 5

转成Date，清除时、分、秒、毫秒，然后直接比较呗。

var timestamp1 = new Date('2020/05/10 12:34:56') * 1 // 1589085296000
var timestamp2 = new Date('2020/05/10 10:20:30') * 1 // 1589077230000
var result = new Date(timestamp1).setHours(0, 0, 0, 0) === new Date(timestamp2).setHours(0, 0, 0, 0)

Answer 6

<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8" />
    <title>the final project</title>
    <style>
    </style>
</head>

<body class="bkgimg">
    <div id="doc">

    </div>
</body>
<script>
    var dok = document.getElementById('doc')
//数据源
    time = [
        {"type":"text","date":1592889320877,"SName":"xxx","content":"1"},
        {"type":"text","date":1592889320877,"SName":"xxx","content":"2"},
        {"type":"text","date":1592889320877,"SName":"xxx","content":"3"}, 
        {"type":"text","date":1592988177000,"SName":"xxx","content":"4"}
    ]
    var arr = []
    console.log(time)
    time.map(item=>{
        console.log('======',setTimes(item.date))
        let obj = {}
        obj.year = setTimes(item.date).years
        obj.mon = setTimes(item.date).mons
        obj.day = setTimes(item.date).days
        obj.time = setTimes(item.date).dds
        arr.push(obj)
        return
    })
    function unique5(array){
        var r = [];
        for(var i = 0, l = array.length; i < l; i++) {
            for(var j = i + 1; j < l; j++)
            if (array[i].year === array[j].year&&array[i].mon === array[j].mon&&array[i].day === array[j].day) j = ++i;
            r.push(array[i]);
        }
        return r;
    }

    console.log('这二十什么？',unique5(arr))
    unique5(arr).map(item=>{
        var div = document.createElement('div');
        div.innerHTML = `<div>${item.year+'-'+item.mon+'-'+item.day}</div>
        <div style="color:blue;padding-left:30px;line-height:60px">${item.time}</div>`
        dok.appendChild(div)
    })
    
    /*
     补零函数:toDB(num)
     参数：num数字
     返回值：小于10的补零返回

 */
function setDb(num) {
    //补零操作
    if (num < 10) {
        return '0' + num;
    } else {
        return '' + num;
    }
}

/*
     秒转成时间：xx天xx时xx分xx秒   ：  -
     setTime(num)
         * 参数： 秒
         * 返回值： {}数据返回(灵活一点)
         
 */
function setTimes(timer) {
    var time = new Date(timer);
    var year = time.getFullYear();//年
    var mon = setDb(time.getMonth() + 1);//0 
    var day = setDb(time.getDate());//24
    var hour = setDb(time.getHours());//时
    var min = setDb(time.getMinutes());//分
    var sec = setDb(time.getSeconds());//秒
    var dd = year+'-'+mon+'-'+day+'-'+hour+':'+min+':'+sec
    return {
        dds:dd,
        years:year,
        mons:mon,
        days:day,

    }

}

</script>
</html>