---
title: Math.E
slug: Web/JavaScript/Reference/Global_Objects/Math/E
translation_of: Web/JavaScript/Reference/Global_Objects/Math/E
---
<div>{{JSRef}}</div>

<p>La costante <strong><code>Math.E</code></strong> rappresenta la base del logaritmo naturale, e, equivale approssimativamente a 2.718.</p>

<p><math display="block"><semantics><mrow><mstyle mathvariant="monospace"><mi>Math.E</mi></mstyle><mo>=</mo><mi>e</mi><mo>≈</mo><mn>2.718</mn></mrow><annotation encoding="TeX">\mathtt{\mi{Math.E}} = e \approx 2.718</annotation></semantics></math></p>

<div>{{EmbedInteractiveExample("pages/js/math-e.html")}}</div>



<div>{{js_property_attributes(0, 0, 0)}}</div>

<h2 id="Descrizione">Descrizione</h2>

<p>Poiché <code>E</code> è una proprietà statica di <code>Math</code>, lo si usa sempre come <code>Math.E</code>, piuttosto che come un metodo di un <code>Oggetto Math</code> appositamente creato (<code>Math</code> non ha un costruttore).</p>

<h2 id="Esempi">Esempi</h2>

<h3 id="Uso_di_Math.E"><code><font face="x-locale-heading-primary, zillaslab, Palatino, Palatino Linotype, x-locale-heading-secondary, serif"><span style="background-color: #333333;">Uso di </span></font>Math.E</code></h3>

<p>Il codice seguente restitusice e:</p>

<pre class="brush: js">function getNapier() {
  return Math.E;
}

getNapier(); // 2.718281828459045
</pre>

<h2 id="Specifiche">Specifiche</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('ES1')}}</td>
   <td>{{Spec2('ES1')}}</td>
   <td>Initial definition. Implemented in JavaScript 1.0.</td>
  </tr>
  <tr>
   <td>{{SpecName('ES5.1', '#sec-15.8.1.1', 'Math.E')}}</td>
   <td>{{Spec2('ES5.1')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('ES6', '#sec-math.e', 'Math.E')}}</td>
   <td>{{Spec2('ES6')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('ESDraft', '#sec-math.e', 'Math.E')}}</td>
   <td>{{Spec2('ESDraft')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="Compatibilità_Browser">Compatibilità Browser</h2>

<p class="hidden">The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out <a href="https://github.com/mdn/browser-compat-data">https://github.com/mdn/browser-compat-data</a> and send us a pull request.</p>

<p>{{Compat("javascript.builtins.Math.E")}}</p>

<h2 id="Vedi_anche">Vedi anche</h2>

<ul>
 <li>{{jsxref("Math.exp()")}}</li>
 <li>{{jsxref("Math.log()")}}</li>
 <li>{{jsxref("Math.log1p()")}}</li>
</ul>