blocks|key|4195868|text|还不完全清楚你想要的是什么。但我能看出你的选择器是错的。此外，您还需要确保在查询文档中的元素之前已加载该文档。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4195869|我将事件侦听器更改为onChange，这样就不会在每次按键时都添加。|4195870|$(document).ready(function()+{
++$('.test+input').on('change',+function()+{
++++var+ok+=+$('.ok');
++++ok.text(parseFloat(ok.text())+%2B+parseFloat($(this).val()))
++})
});|code-block|syntax|javascript|4195871|这是它运行的plunker。|offset|length|4195872|这是你要问的另一个猜测，plunker。它将初始值存储为属性。|4195873|$(document).ready(function()+{
++var+ok+=+$('.ok');

++$('.ok').text(ok.attr('data-initial-value'));
++$('.test+input').on('change',+function()+{
++++ok.text(parseFloat(ok.attr('data-initial-value'))+%2B+parseFloat($(this).val()))
++})
});

<div+class="ok"+data-initial-value="6"+style="background-color:+white">
++</div>|4195874|entityMap|0|LINK|mutability|MUTABLE|url|https://plnkr.co/edit/y0JYhx6IroFK6mWSWo59?p=preview&plnkr=next&utm_source=legacy&utm_medium=banner&utm_campaign=next|1^0|0|0|0|6|7|0|0|C|7|1|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|10|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|11|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|12|8|@]|9|@$K|13|L|14|1|15]]|A|$]]|$1|M|3|N|5|6|7|16|8|@]|9|@$K|17|L|18|1|19]]|A|$]]|$1|O|3|P|5|F|7|1A|8|@]|9|@]|A|$G|H]]|$1|Q|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]|Y|$5|T|U|V|A|$W|X]]]]

<p>It's not entirely clear what you are asking for. But I can see your selector is wrong. Also you want to make sure the document is loaded before you query elements in it.</p>

<p>I change the event listener to an onChange so that the addition doesn't happen for every keypress.</p>

<pre><code>$(document).ready(function() {
  $('.test input').on('change', function() {
    var ok = $('.ok');
    ok.text(parseFloat(ok.text()) + parseFloat($(this).val()))
  })
});
</code></pre>

<p>Here's a <a href="https://plnkr.co/edit/y0JYhx6IroFK6mWSWo59?p=preview&amp;plnkr=next&amp;utm_source=legacy&amp;utm_medium=banner&amp;utm_campaign=next" rel="nofollow noreferrer">plunker</a> of it running.<br>
Here's another guess at what you're asking, <a href="https://plnkr.co/edit/y0JYhx6IroFK6mWSWo59?p=preview&amp;plnkr=next&amp;utm_source=legacy&amp;utm_medium=banner&amp;utm_campaign=next" rel="nofollow noreferrer">plunker</a>. Which stores the initial value as an attribute.</p>

<pre><code>$(document).ready(function() {
  var ok = $('.ok');

  $('.ok').text(ok.attr('data-initial-value'));
  $('.test input').on('change', function() {
    ok.text(parseFloat(ok.attr('data-initial-value')) + parseFloat($(this).val()))
  })
});

&lt;div class="ok" data-initial-value="6" style="background-color: white"&gt;
  &lt;/div&gt;
</code></pre>


blocks|key|4195936|text|正如@Doug建议的那样，您可以使用属性来存储初始值：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4195937|​|4195938|$('input').on('input',+function()+{
++var+ok+=+$('.ok');
++ok.text(%2B(ok.attr('i'))+%2B+%2B($(this).val()+%7C%7C+0))
})|code-block|syntax|javascript|4195939|<script+src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<div+class="ok"+i="6">6</div>
<input+type="text"+/>|4195940|4195941|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|P|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|K|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|L|3|-4|5|6|7|S|8|@]|9|@]|A|$]]]|M|$]]

<p>As @Doug suggested, you might use an attribute to store the initial value:</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>$('input').on('input', function() {
  var ok = $('.ok');
  ok.text(+(ok.attr('i')) + +($(this).val() || 0))
})</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;div class="ok" i="6"&gt;6&lt;/div&gt;
&lt;input type="text" /&gt;</code></pre>
</div>
</div>
</p>


blocks|key|4196022|text|感谢所有人的帮助和提示，并为混乱的解释道歉…|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4196023|这就是我所做的，它起作用了:当我聚焦时，我将旧值放在一个属性中，然后当我将数字相加时，我用存储的数字减去我的实际数字。|4196024|​|4196025|$('.test+input').on('focus',+function(){

$(this).attr('value',+$(this).val());

});


$('.test+input').on('change',+function(){
++++var+valActuelle+=+0;
++++if($(this).attr('value')+!==+''){
++++++++valActuelle+=+$(this).attr('value');
++++}

var+ok+=+$('.ok');
ok.text((+parseFloat(ok.text())++-+parseFloat(valActuelle))+%2B+parseFloat($(this).val())+);
})|code-block|syntax|javascript|4196026|<script+src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div+class="ok"+style="background-color:+white">
6
</div>
<div+class="test">
<input+type="text"/>
</div>|4196027|4196028|它只有在你失去焦点的情况下才有效，但在我的情况下，我总是失去焦点|4196029|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|S|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|T|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|U|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|H|7|V|8|@]|9|@]|A|$I|J]]|$1|M|3|E|5|6|7|W|8|@]|9|@]|A|$]]|$1|N|3|O|5|6|7|X|8|@]|9|@]|A|$]]|$1|P|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|Q|$]]

<p>Thanks all for helping and hints, and sorry for messy explanations...</p>

<p>Here is what I did and it works : when I focus I put the old value in an attribute then when I add numbers I substract my actuel number with the stored number.</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>$('.test input').on('focus', function(){

$(this).attr('value', $(this).val());

});


$('.test input').on('change', function(){
    var valActuelle = 0;
    if($(this).attr('value') !== ''){
        valActuelle = $(this).attr('value');
    }

var ok = $('.ok');
ok.text(( parseFloat(ok.text())  - parseFloat(valActuelle)) + parseFloat($(this).val()) );
})</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;div class="ok" style="background-color: white"&gt;
6
&lt;/div&gt;
&lt;div class="test"&gt;
&lt;input type="text"/&gt;
&lt;/div&gt;</code></pre>
</div>
</div>
</p>

<p>It works only if you lose the focus but in my case I'm ALWAYS losing the focus</p>


<p>I have a value that I must change dynamically : the original value is 6 and I can customize it. If I put 7 on an inputbox, I now have 13. When I add another number, for example 71 my value change by 13 + 71. I want to substract the 13 with the previous value (7) to get my original one which is 6. </p>

<p>Here is my snippet : </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>$('.test :input').on('input', function(){

var ok = $('.ok');
ok.text(parseFloat(ok.text()) + parseFloat($(this).val()))
})</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;div class="ok" style="background-color: white"&gt;
6
&lt;/div&gt;
&lt;div class="test"&gt;
&lt;input type="text"/&gt;
&lt;/div&gt;</code></pre>
</div>
</div>
</p>

<p>If you try to type 45 you should have 51 and you have 55.</p>

<p>I already tried with "focusing" as shown on some threads but I'm not leaving the input so it doesn't work. I don't know how to get my previous value.</p>


Get previous value on input event

我有一个必须动态更改的值:原始值是6，我可以对其进行自定义。如果我把7放在输入框上，我现在就有13。当我添加另一个数字时，比如71，我的值就变成了13 + 71。我想用前面的值(7)减去13，得到原来的值6。下面是我的代码片段：​$('.test :input').on('input', function(){var ...

问获取输入事件的上一个值
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