有没有比下面的pausecomp函数(取自此处)更好的方法来设计JavaScript中的睡眠?

function pausecomp(millis)
{
    var date = new Date();
    var curDate = null;
    do { curDate = new Date(); }
    while(curDate-date < millis);
}

这不是JavaScript中的Sleep的重复-动作之间的延迟;我希望在函数的中间有一个真正的睡眠,而不是在代码执行之前有一段延迟。


当前回答

万一你真的需要睡眠()来测试什么。但要注意,在调试过程中,大多数时候它都会使浏览器崩溃——这可能就是为什么无论如何都需要它的原因。在生产模式下,我将注释掉这个函数。

function pauseBrowser(millis) {
    var date = Date.now();
    var curDate = null;
    do {
        curDate = Date.now();
    } while (curDate-date < millis);
}

不要在循环中使用new Date(),除非你想浪费内存、处理能力、电池,甚至可能浪费设备的寿命。

其他回答

如果您想要在所有浏览器上都可用的代码,请使用setTimeout()和clearTimeout(()。如果您深入阅读答案,您可能会注意到,接受的答案打破了Internet Explorer 11中所有JavaScript编译,使用此解决方案后,大约有5%的用户仍在使用此积极开发的浏览器并需要支持。

这几乎打破了一切。已知有报道称箭头函数破坏了Drupal、WordPress、Amazon AWS、IBM等软件的Internet Explorer 11功能,甚至在Stack Overflow上也有专门的讨论。

看看吧。。。

使用setTimeout()和clearTimeout(。。。

工作JSBin演示

var超时;功能休眠(延迟){if(超时){clearTimeout(超时);}timeout=setTimeout(函数){myFunction();},延迟);}console.log(“休眠1秒”);睡眠(1000);函数myFunction(){console.log(“睡眠了1秒钟!”);}

干得好。正如代码所说,不要做一个糟糕的开发人员,在网站上使用它。这是一个开发实用函数。

// Basic sleep function based on ms.
// DO NOT USE ON PUBLIC FACING WEBSITES.
function sleep(ms) {
    var unixtime_ms = new Date().getTime();
    while(new Date().getTime() < unixtime_ms + ms) {}
}

我在JavaScript sleep/wait上搜索了很多网页。。。如果你想让JavaScript“RUN,DELAY,RUN”。。。大多数人得到的要么是“RUN,RUN(无用的东西),RUN”,要么是“RUN,RUN+延迟RUN”。。。

我想:这是一个有效的解决方案。。。但你必须把你的跑步代码切碎…:是的,我知道,这只是一个更容易理解的重构。。。还

示例1:

<html>
<body>
<div id="id1">DISPLAY</div>

<script>
// JavaScript sleep by "therealdealsince1982"; copyrighted 2009
// setInterval
var i = 0;

function run() {
    // Pieces of codes to run
    if (i == 0){document.getElementById("id1").innerHTML= "<p>code segment " + i + " is ran</p>"; }
    if (i == 1){document.getElementById("id1").innerHTML= "<p>code segment " + i + " is ran</p>"; }
    if (i == 2){document.getElementById("id1").innerHTML= "<p>code segment " + i + " is ran</p>"; }
    if (i >2){document.getElementById("id1").innerHTML= "<p>code segment " + i + " is ran</p>"; }
    if (i == 5){document.getElementById("id1").innerHTML= "<p>all code segment finished running</p>"; clearInterval(t); } // End interval, stops run
    i++; // Segment of code finished running, next...
}

run();
t = setInterval("run()", 1000);

</script>
</body>
</html>

示例2:

<html>
<body>
<div id="id1">DISPLAY</div>

<script>
// JavaScript sleep by "therealdealsince1982"; copyrighted 2009
// setTimeout
var i = 0;

function run() {
    // Pieces of codes to run, can use switch statement
    if (i == 0){document.getElementById("id1").innerHTML= "<p>code segment " + i + " ran</p>"; sleep(1000);}
    if (i == 1){document.getElementById("id1").innerHTML= "<p>code segment " + i + " ran</p>"; sleep(2000);}
    if (i == 2){document.getElementById("id1").innerHTML= "<p>code segment " + i + " ran</p>"; sleep(3000);}
    if (i == 3){document.getElementById("id1").innerHTML= "<p>code segment " + i + " ran</p>";} //stops automatically
    i++;
}

function sleep(dur) {t=setTimeout("run()", dur);} // Starts flow control again after 'dur'

run(); // Starts
</script>
</body>
</html>

示例3:

<html>
<body>
<div id="id1">DISPLAY</div>

<script>
// JavaScript sleep by "therealdealsince1982"; copyrighted 2009
// setTimeout
var i = 0;

function flow() {
    run(i);
    i++; // Code segment finished running, increment i; can put elsewhere
    sleep(1000);
    if (i == 5) {clearTimeout(t);} // Stops flow, must be after sleep()
}

function run(segment) {
    // Pieces of codes to run, can use switch statement
    if (segment == 0){document.getElementById("id1").innerHTML= "<p>code segment " + segment + " is ran</p>"; }
    if (segment == 1){document.getElementById("id1").innerHTML= "<p>code segment " + segment + " is ran</p>"; }
    if (segment == 2){document.getElementById("id1").innerHTML= "<p>code segment " + segment + " is ran</p>"; }
    if (segment >2){document.getElementById("id1").innerHTML= "<p>code segment "+ segment +" is ran</p>"; }
}

function sleep(dur) {t=setTimeout("flow()", dur);} // Starts flow control again after 'dur'

flow(); // Starts flow
</script>
</body>
</html>

示例4:

<html>
<body>
<div id="id1">DISPLAY</div>

<script>
// JavaScript sleep by "therealdealsince1982"; copyrighted 2009
// setTimeout, switch
var i = 0;

function flow() {
    switch(i)
    {
        case 0:
            run(i);
            sleep(1000);
            break;
        case 1:
            run(i);
            sleep(2000);
            break;
        case 5:
            run(i);
            clearTimeout(t); // Stops flow
            break;
        default:
            run(i);
            sleep(3000);
            break;
    }
}

function run(segment) {
    // Pieces of codes to run, can use switch statement
    if (segment == 0){document.getElementById("id1").innerHTML= "<p>code segment " + segment + " is ran</p>"; }
    if (segment == 1){document.getElementById("id1").innerHTML= "<p>code segment " + segment + " is ran</p>"; }
    if (segment == 2){document.getElementById("id1").innerHTML= "<p>code segment " + segment + " is ran</p>"; }
    if (segment >2){document.getElementById("id1").innerHTML= "<p>code segment " + segment + " is ran</p>"; }
    i++; // Current segment of code finished running, next...
}

function sleep(dur) {t=setTimeout("flow()", dur);} // Starts flow control again after 'dur'

flow(); // Starts flow control for first time...
</script>
</body>
</html>

如果你想要比setTimeout和setInterval更简单的函数,你可以将它们包装在函数中,只需颠倒参数的顺序,给它们起个好听的名字:

function after(ms, fn){ setTimeout(fn, ms); }
function every(ms, fn){ setInterval(fn, ms); }

CoffeeScript版本:

after = (ms, fn)-> setTimeout fn, ms
every = (ms, fn)-> setInterval fn, ms

然后,您可以将它们很好地用于匿名函数:

after(1000, function(){
    console.log("it's been a second");
    after(1000, function(){
        console.log("it's been another second");
    });
});

现在它很容易读成“N毫秒后,…”(或“每N毫秒,…”)

简短的答案是否定的,而不是JavaScript本身。您的解决方案似乎是不让控制权回归环境的唯一途径。

如果环境不支持事件,这是必要的。他们可能也不支持setTimeout。

如果您处于事件驱动环境(如浏览器或Node.js)中,setTimeout绝对是最好的方法。