倒计时的两种方案

export const countDown=(time)=>{
    const t = (new Date(time).getTime() - new Date().getTime())/1000;
    const days = parseInt(t/3600/24);
    const hours = parseInt(t/60/60%24);
    const minutes = parseInt(t/60%60);
    const seconds = parseInt(t%60);
    const h = hours<10?`0${hours}`:hours;
    const m = minutes<10?`0${minutes}`:minutes;
    const s = seconds<10?`0${seconds}`:seconds;
    return (days>0&&`${days}天${h}小时${m}分钟${s}秒`)||
        (hours>0&&`${h}小时${m}分钟${s}秒`)||
        (minutes>0&&`${m}分钟${s}秒`)||
        (seconds>0&&`${s}秒`)
};

export const countDown2=(time)=>{
    const t = parseInt(new Date(time).getTime()/1000 - new Date().getTime()/1000);
    const days = parseInt(t/(60*60*24));
    const hours = parseInt(t/(60*60) - days*24);
    const minutes = parseInt(t/60 - hours*60 - days*24*60);
    const seconds = parseInt(t - minutes*60 - hours*3600 - days*24*3600);
    const h = hours<10?`0${hours}`:hours;
    const m = minutes<10?`0${minutes}`:minutes;
    const s = seconds<10?`0${seconds}`:seconds;
    return (days>0&&`${days}天${h}小时${m}分钟${s}秒`)||
        (hours>0&&`${h}小时${m}分钟${s}秒`)||
        (minutes>0&&`${m}分钟${s}秒`)||
        (seconds>0&&`${s}秒`)
};