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());

我喜欢Powtac的答案，但我想在angular.js中使用它，所以我用他的代码创建了一个过滤器。

.filter('HHMMSS', ['$filter', function ($filter) {
    return function (input, decimals) {
        var sec_num = parseInt(input, 10),
            decimal = parseFloat(input) - sec_num,
            hours   = Math.floor(sec_num / 3600),
            minutes = Math.floor((sec_num - (hours * 3600)) / 60),
            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;}
        var time    = hours+':'+minutes+':'+seconds;
        if (decimals > 0) {
            time += '.' + $filter('number')(decimal, decimals).substr(2);
        }
        return time;
    };
}])

它在功能上是相同的，除了我添加了一个可选的小数字段来显示小数秒。像使用其他过滤器一样使用它:

{{elapsedTime | HHMMSS}}显示:01:23:45

{{elapsedTime | HHMMSS: 3}}显示:01:23:45.678

secToHHMM(number: number) {
    debugger;
    let hours = Math.floor(number / 3600);
    let minutes = Math.floor((number - (hours * 3600)) / 60);
    let seconds = number - (hours * 3600) - (minutes * 60);
    let H, M, S;
    if (hours < 10) H = ("0" + hours);
    if (minutes < 10) M = ("0" + minutes);
    if (seconds < 10) S = ("0" + seconds);
    return (H || hours) + ':' + (M || minutes) + ':' + (S || seconds);
}

我喜欢第一个答案。 这里有一些优化:

源数据是一个数字。不需要额外的计算。 过多的计算

结果代码:

Number.prototype.toHHMMSS = function () {
    var seconds = Math.floor(this),
        hours = Math.floor(seconds / 3600);
    seconds -= hours*3600;
    var minutes = Math.floor(seconds / 60);
    seconds -= minutes*60;

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

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

新的日期().toString()。分割(" ")[4];

结果15:08:03