blocks|key|1261230|text|变量timeInterval在$(document).ready(...)中|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1261231|试试这个：|1261232|var+timeInterval;

$(document).ready(function()+{
++++updateClock();
++++timeInterval+=+setInterval(updateClock(),+1000);
});

var+ms+=+5000;

function+updateClock()+{
++++ms+-=+1000;
++++var+minutes+=+Math.floor(ms+/+1000+/+60);
++++var+seconds+=+Math.floor((ms+/+1000)+%25+60);
++++$('#minutes').html(minutes);
++++$('#seconds').html(seconds);
++++if+(ms+<=+0)+{
++++++++alert('Time+is+up!');
++++++++clearInterval(timeInterval);
++++};
}|code-block|syntax|javascript|1261233|entityMap^0|2|C|F|M|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|T|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|U|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

<p>Your variable <code>timeInterval</code> is inside <code>$(document).ready(...)</code></p>

<p>Try this:</p>

<pre><code>var timeInterval;

$(document).ready(function() {
    updateClock();
    timeInterval = setInterval(updateClock(), 1000);
});

var ms = 5000;

function updateClock() {
    ms -= 1000;
    var minutes = Math.floor(ms / 1000 / 60);
    var seconds = Math.floor((ms / 1000) % 60);
    $('#minutes').html(minutes);
    $('#seconds').html(seconds);
    if (ms &lt;= 0) {
        alert('Time is up!');
        clearInterval(timeInterval);
    };
}
</code></pre>


blocks|key|1261266|text|根据MDN文档|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1261267|var+intervalID+=+window.setInterval(func，delay，param1，param2，.)；
var+intervalID+=window.setInterval(码，延迟)；|blockquote|1261268|其中：|1261269|功能
每延迟毫秒执行一次的函数。|1261270|这意味着，如果使用第一个参数调用此函数，则如下所示：|1261271|updateClock()|code-block|syntax|javascript|1261272|执行updateClock函数，并将结果代码返回给setInterval函数。但是，因为这样的函数(即:+updateClock)返回未定义的函数，所以setInterval在下一次将没有什么可执行的。|1261273|对于另一个问题(即:局部变量)，可以这样将变量"timeInterval“声明为全局函数：|1261274|window.timeInterval+=+setInterval(updateClock,+1000);|1261275|这将确保定时器处理程序可以立即使用全局变量(即:+timeInterval)的值。|1261276|例子：|1261277|​|1261278|$(document).ready(function()+{
++window.timeInterval+=+setInterval(updateClock,+1000);
});

var+ms+=+10000;

function+updateClock()+{
++ms+-=+1000;
++var+minutes+=+Math.floor(ms+/+1000+/+60);
++var+seconds+=+Math.floor((ms+/+1000)+%25+60);
++$('#minutes').text(minutes);
++$('#seconds').text(seconds);
++if+(ms+<=+0)+{
++++setTimeout(function()+{+//+this+to+refresh+before+alert
++++++alert('Time+is+up!');
++++},+10);
++++clearInterval(timeInterval);
++};
}|1261279|<script+src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>


<span+id="minutes">0</span>:<span+id="seconds">10</span>|1261280|1261281|您还可以缓存min和sec+dom元素，而不是每次搜索它们：|1261282|1261283|$(document).ready(function()+{
++var+minObj+=+$('#minutes');
++var+secObj+=+$('#seconds')
++window.timeInterval+=+setInterval(function+()+{
++++updateClock(minObj,+secObj);
++},+1000);
});

var+ms+=+10000;

function+updateClock(minObj,+secObj)+{
++ms+-=+1000;
++var+minutes+=+Math.floor(ms+/+1000+/+60);
++var+seconds+=+Math.floor((ms+/+1000)+%25+60);
++minObj.text(minutes);
++secObj.text(seconds);
++if+(ms+<=+0)+{
++++setTimeout(function()+{+//+this+to+refresh+before+alert
++++++alert('Time+is+up!');
++++},+10);
++++clearInterval(timeInterval);
++};
}|1261284|<script+src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>


<span+id="minutes">0</span>:<span+id="seconds">10</span>|1261285|1261286|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en-US/docs/Web/API/WindowTimers/setInterval^0|2|5|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1O|8|@]|9|@$A|1P|B|1Q|1|1R]]|C|$]]|$1|D|3|E|5|F|7|1S|8|@]|9|@]|C|$]]|$1|G|3|H|5|6|7|1T|8|@]|9|@]|C|$]]|$1|I|3|J|5|F|7|1U|8|@]|9|@]|C|$]]|$1|K|3|L|5|6|7|1V|8|@]|9|@]|C|$]]|$1|M|3|N|5|O|7|1W|8|@]|9|@]|C|$P|Q]]|$1|R|3|S|5|6|7|1X|8|@]|9|@]|C|$]]|$1|T|3|U|5|6|7|1Y|8|@]|9|@]|C|$]]|$1|V|3|W|5|O|7|1Z|8|@]|9|@]|C|$P|Q]]|$1|X|3|Y|5|6|7|20|8|@]|9|@]|C|$]]|$1|Z|3|10|5|6|7|21|8|@]|9|@]|C|$]]|$1|11|3|12|5|6|7|22|8|@]|9|@]|C|$]]|$1|13|3|14|5|O|7|23|8|@]|9|@]|C|$P|Q]]|$1|15|3|16|5|O|7|24|8|@]|9|@]|C|$P|Q]]|$1|17|3|12|5|6|7|25|8|@]|9|@]|C|$]]|$1|18|3|19|5|6|7|26|8|@]|9|@]|C|$]]|$1|1A|3|12|5|6|7|27|8|@]|9|@]|C|$]]|$1|1B|3|1C|5|O|7|28|8|@]|9|@]|C|$P|Q]]|$1|1D|3|1E|5|O|7|29|8|@]|9|@]|C|$P|Q]]|$1|1F|3|12|5|6|7|2A|8|@]|9|@]|C|$]]|$1|1G|3|-4|5|6|7|2B|8|@]|9|@]|C|$]]]|1H|$1I|$5|1J|1K|1L|C|$1M|1N]]]]

<p>According to <a href="https://developer.mozilla.org/en-US/docs/Web/API/WindowTimers/setInterval" rel="nofollow noreferrer">MDN doc</a>:</p>
<blockquote>
<p>var intervalID = window.setInterval(func, delay[, param1, param2, ...]);</p>
<p>var intervalID = window.setInterval(code, delay);</p>
</blockquote>
<p>where:</p>
<blockquote>
<p>func</p>
<pre><code>      A function to be executed every delay milliseconds.
</code></pre>
</blockquote>
<p>This means that if you call this function with first parameter like:</p>
<pre><code>updateClock()
</code></pre>
<p>the updateClock function is executed and the result code is returned to the setInterval function. But, because such a function (i.e.: updateClock) returns undefined, the setInterval will have nothing to execute the next times.</p>
<p>For the other problem (i.e.: local variable) you may declare the variable &quot;timeInterval&quot; as a global function in this way:</p>
<pre><code>window.timeInterval = setInterval(updateClock, 1000);
</code></pre>
<p>This will assure the value of the global variaable (i.e.: timeInterval) is available to the timer handler immediately.</p>
<p>The example:</p>
<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>$(document).ready(function() {
  window.timeInterval = setInterval(updateClock, 1000);
});

var ms = 10000;

function updateClock() {
  ms -= 1000;
  var minutes = Math.floor(ms / 1000 / 60);
  var seconds = Math.floor((ms / 1000) % 60);
  $('#minutes').text(minutes);
  $('#seconds').text(seconds);
  if (ms &lt;= 0) {
    setTimeout(function() { // this to refresh before alert
      alert('Time is up!');
    }, 10);
    clearInterval(timeInterval);
  };
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"&gt;&lt;/script&gt;


&lt;span id="minutes"&gt;0&lt;/span&gt;:&lt;span id="seconds"&gt;10&lt;/span&gt;</code></pre>
</div>
</div>
</p>
<p>You might also cache your min and sec dom elements instead to searches for them every time:</p>
<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>$(document).ready(function() {
  var minObj = $('#minutes');
  var secObj = $('#seconds')
  window.timeInterval = setInterval(function () {
    updateClock(minObj, secObj);
  }, 1000);
});

var ms = 10000;

function updateClock(minObj, secObj) {
  ms -= 1000;
  var minutes = Math.floor(ms / 1000 / 60);
  var seconds = Math.floor((ms / 1000) % 60);
  minObj.text(minutes);
  secObj.text(seconds);
  if (ms &lt;= 0) {
    setTimeout(function() { // this to refresh before alert
      alert('Time is up!');
    }, 10);
    clearInterval(timeInterval);
  };
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"&gt;&lt;/script&gt;


&lt;span id="minutes"&gt;0&lt;/span&gt;:&lt;span id="seconds"&gt;10&lt;/span&gt;</code></pre>
</div>
</div>
</p>


<p>I'm working on a simple timer using JS. When the timer hits 0, I want "time up!" to pop up.</p>

<pre><code>$(document).ready(function() {
    updateClock();
    var timeInterval = setInterval(updateClock(), 1000);
});

var ms = 5000;

function updateClock() {
    ms -= 1000;
    var minutes = Math.floor(ms / 1000 / 60);
    var seconds = Math.floor((ms / 1000) % 60);
    $('#minutes').html(minutes);
    $('#seconds').html(seconds);
    if (ms &lt;= 0) {
        alert('Time is up!');
        clearInterval(timeInterval);
    };
}
</code></pre>

<p>Right now, the alert pops up multiple times. I suspect it's because I'm using <code>clearInterval()</code> incorrectly—when I open up the developer console, it says: </p>

<blockquote>
  <p>"Uncaught ReferenceError: timeInterval is not defined at updateClock."</p>
</blockquote>

<p>However, I'm not sure what to change to make it function correctly.</p>


Alert window popping up multiple times when timer finishes

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我正在用JS做一个简单的计时器。当计时器命中0时，我想要“时间向上！”突然出现。$(document).ready(function() {    updateClock();    var timeInterval = setInterval(updateClock(), 1000);});var ms = 5000...

问当计时器结束时，警报窗口会多次弹出。
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问当计时器结束时，警报窗口会多次弹出。EN