jQuery Spinner - get value from spinner
<p>I am using  <a href="https://github.com/vsn4ik/jquery.spinner" rel="nofollow noreferrer">jQuery Spinner</a> and dont know how to get value from spinner to use in javascript code. </p>

<p>JS - in separate library i need to call value</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
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<pre class="snippet-code-js lang-js prettyprint-override"><code>function calculate (){
    var result = 15 * HERE I NEED VALUE! ;
   
 }</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="input-group spinner" data-trigger="spinner"&gt;
          &lt;input type="text" class="form-control text-center" value="0" data-rule="quantity"&gt;
          &lt;div class="input-group-addon"&gt;
            &lt;a href="javascript:;" class="spin-up" data-spin="up"&gt;&lt;i class="fa fa-caret-up"&gt;&lt;/i&gt;&lt;/a&gt;
            &lt;a href="javascript:;" class="spin-down" data-spin="down"&gt;&lt;i class="fa fa-caret-down"&gt;&lt;/i&gt;&lt;/a&gt;
          &lt;/div&gt;
        &lt;/div&gt;</code></pre>
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