JS判断时间几天前，几小时，几分，几秒前

js 仿朋友圈的时间显示 刚刚 几天前，几小时，几分，几秒前

function getDateDiff(dateStr) {
        var publishTime = getDateTimeStamp(dateStr) / 1000,
        d_seconds,
        d_minutes,
        d_hours,
        d_days,
        timeNow = parseInt(new Date().getTime() / 1000),
        d,
 
        date = new Date(publishTime * 1000),
        Y = date.getFullYear(),
        M = date.getMonth() + 1,
        D = date.getDate(),
        H = date.getHours(),
        m = date.getMinutes(),
        s = date.getSeconds();
        //小于10的在前面补0
        if (M < 10) {
                M = '0' + M;
        }
        if (D < 10) {
                D = '0' + D;
        }
        if (H < 10) {
                H = '0' + H;
        }
        if (m < 10) {
                m = '0' + m;
        }
        if (s < 10) {
                s = '0' + s;
        }
 
        d = timeNow - publishTime;
        d_days = parseInt(d / 86400);
        d_hours = parseInt(d / 3600);
        d_minutes = parseInt(d / 60);
        d_seconds = parseInt(d);
 
        if (d_days > 0 && d_days < 3) {
                return d_days + '天前';
        } else if (d_days <= 0 && d_hours > 0) {
                return d_hours + '小时前';
        } else if (d_hours <= 0 && d_minutes > 0) {
                return d_minutes + '分钟前';
        } else if (d_seconds < 60) {
                if (d_seconds <= 0) {
                        return '刚刚';
                } else {
                        return d_seconds + '秒前';
                }
        } else if (d_days >= 3 && d_days < 30) {
                return M + '-' + D + ' ' + H + ':' + m;
        } else if (d_days >= 30) {
                return Y + '-' + M + '-' + D + ' ' + H + ':' + m;
        }
}
 
function getDateTimeStamp(dateStr) {

          // 如果时间格式为2020/07/09 21:43:19.000  需要去掉.000 不然ios和firefox会有问题

return Date.parse(dateStr.replace(/-/gi, "/"));
}　　

console.log(this.getDateDiff("2020-07-03 10:03:19.000"));