我最喜欢Webjins的答案，所以我扩展了它以显示d后缀的日子，使显示有条件，并包括一个s后缀的普通秒:

function sec2str(t){
    var d = Math.floor(t/86400),
        h = ('0'+Math.floor(t/3600) % 24).slice(-2),
        m = ('0'+Math.floor(t/60)%60).slice(-2),
        s = ('0' + t % 60).slice(-2);
    return (d>0?d+'d ':'')+(h>0?h+':':'')+(m>0?m+':':'')+(t>60?s:s+'s');
}

返回"3d 16:32:12"或"16:32:12"或"32:12"或"12s"

块上的字符串有一个新方法:padStart

const str = '5';
str.padStart(2, '0'); // 05

下面是一个示例用例:用4行JavaScript编写YouTube持续时间

毫秒到持续时间，简单的方法是:

// To have leading zero digits in strings.
function pad(num, size) {
    var s = num + "";
    while (s.length < size) s = "0" + s;
    return s;
}

// ms to time/duration
msToDuration = function(ms){
    var seconds = ms / 1000;
    var hh = Math.floor(seconds / 3600),
    mm = Math.floor(seconds / 60) % 60,
    ss = Math.floor(seconds) % 60,
    mss = ms % 1000;
    return pad(hh,2)+':'+pad(mm,2)+':'+pad(ss,2)+'.'+pad(mss,3);
}

它将327577转换为00:05:27.577。

更新

另一种不同场景的方法:

toHHMMSS = function (n) {
    var sep = ':',
        n = parseFloat(n),
        sss = parseInt((n % 1)*1000),
        hh = parseInt(n / 3600);
    n %= 3600;
    var mm = parseInt(n / 60),
        ss = parseInt(n % 60);
    return pad(hh,2)+sep+pad(mm,2)+sep+pad(ss,2)+'.'+pad(sss,3);
    function pad(num, size) {
        var str = num + "";
        while (str.length < size) str = "0" + str;
        return str;
    }
}

toHHMMSS(6315.077) // Return 01:45:15.077

这是另一个版本，也处理天数:

function FormatSecondsAsDurationString( seconds )
{
    var s = "";

    var days = Math.floor( ( seconds / 3600 ) / 24 );
    if ( days >= 1 )
    {
        s += days.toString() + " day" + ( ( days == 1 ) ? "" : "s" ) + " + ";
        seconds -= days * 24 * 3600;
    }

    var hours = Math.floor( seconds / 3600 );
    s += GetPaddedIntString( hours.toString(), 2 ) + ":";
    seconds -= hours * 3600;

    var minutes = Math.floor( seconds / 60 );
    s += GetPaddedIntString( minutes.toString(), 2 ) + ":";
    seconds -= minutes * 60;

    s += GetPaddedIntString( Math.floor( seconds ).toString(), 2 );

    return s;
}

function GetPaddedIntString( n, numDigits )
{
    var nPadded = n;
    for ( ; nPadded.length < numDigits ; )
    {
        nPadded = "0" + nPadded;
    }

    return nPadded;
}

String.prototype.toHHMMSS = function () {
    var sec_num = parseInt(this, 10); // don't forget the second param
    var hours   = Math.floor(sec_num / 3600);
    var minutes = Math.floor((sec_num - (hours * 3600)) / 60);
    var seconds = sec_num - (hours * 3600) - (minutes * 60);

    if (hours   < 10) {hours   = "0"+hours;}
    if (minutes < 10) {minutes = "0"+minutes;}
    if (seconds < 10) {seconds = "0"+seconds;}
    return hours+':'+minutes+':'+seconds;
}

你现在可以这样使用它:

alert("5678".toHHMMSS());

工作代码片段:

String.prototype.toHHMMSS = function () { var sec_num = parseInt(this, 10); // don't forget the second param var hours = Math.floor(sec_num / 3600); var minutes = Math.floor((sec_num - (hours * 3600)) / 60); var seconds = sec_num - (hours * 3600) - (minutes * 60); if (hours < 10) {hours = "0"+hours;} if (minutes < 10) {minutes = "0"+minutes;} if (seconds < 10) {seconds = "0"+seconds;} return hours + ':' + minutes + ':' + seconds; } console.log("5678".toHHMMSS());

function formatTime(seconds) {
    return [
        parseInt(seconds / 60 / 60),
        parseInt(seconds / 60 % 60),
        parseInt(seconds % 60)
    ]
        .join(":")
        .replace(/\b(\d)\b/g, "0$1")
}