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---
title: Number
slug: Web/JavaScript/Reference/Global_Objects/Number
translation_of: Web/JavaScript/Reference/Global_Objects/Number
---
<ol>
<li>{{JSRef}}</li>
</ol>
<div><strong><code>Number</code></strong> is a <a href="/en-US/docs/Glossary/Primitive#Primitive_wrapper_objects_in_JavaScript">primitive wrapper object</a> used to represent and manipulate numbers like <code>37</code> or <code>-9.25</code>.</div>
<div></div>
<div></div>
<p>The <strong><code>Number</code></strong> constructor contains constants and methods for working with numbers. Values of other types can be converted to numbers using the<strong> </strong><strong><code>Number()</code> function</strong>.</p>
<p>The JavaScript <strong>Number</strong> type is a <a href="https://en.wikipedia.org/wiki/Floating-point_arithmetic">double-precision 64-bit binary format IEEE 754</a> value, like <code>double</code> in Java or C#. This means it can represent fractional values, but there are some limits to what it can store. A Number only keeps about 17 decimal places of precision; arithmetic is subject to <a href="https://en.wikipedia.org/wiki/Floating-point_arithmetic#Representable_numbers,_conversion_and_rounding">rounding</a>. The largest value a Number can hold is about 1.8×10<sup>308</sup>. Numbers beyond that are replaced with the special Number constant {{jsxref("Infinity")}}.</p>
<p>A number literal like <code>37</code> in JavaScript code is a floating-point value, not an integer. There is no separate integer type in common everyday use. (JavaScript now has a {{jsxref("BigInt")}} type, but it was not designed to replace Number for everyday uses. <code>37</code> is still a Number, not a BigInt.)</p>
<dl>
</dl>
<h2 id="Description">Description</h2>
<p>When used as a function, <code>Number(value)</code> converts a string or other value to the Number type. If the value can't be converted, it returns {{jsxref("NaN")}}.</p>
<h3 id="Literal_syntax">Literal syntax</h3>
<pre class="brush: js notranslate">123 // one-hundred twenty-three
123.0 // same
123 === 123.0 // true</pre>
<h3 id="Function_syntax">Function syntax</h3>
<pre class="brush: js notranslate">Number('123') // returns the number 123
Number('123') === 123 // true
Number("unicorn") // NaN
Number(undefined) // NaN
</pre>
<h2 id="Constructor">Constructor</h2>
<dl>
<dt><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/Number"><code>Number()</code></a></dt>
<dd>Creates a new <code>Number</code> value.</dd>
</dl>
<h2 id="Static_properties">Static properties</h2>
<dl>
<dt>{{jsxref("Number.EPSILON")}}</dt>
<dd>The smallest interval between two representable numbers.</dd>
<dt>{{jsxref("Number.MAX_SAFE_INTEGER")}}</dt>
<dd>The maximum safe integer in JavaScript (<code>2<sup>53</sup> - 1</code>).</dd>
<dt>{{jsxref("Number.MAX_VALUE")}}</dt>
<dd>The largest positive representable number.</dd>
<dt>{{jsxref("Number.MIN_SAFE_INTEGER")}}</dt>
<dd>The minimum safe integer in JavaScript (<code>-(2<sup>53</sup> - 1)</code>).</dd>
<dt>{{jsxref("Number.MIN_VALUE")}}</dt>
<dd>The smallest positive representable number—that is, the positive number closest to zero (without actually being zero).</dd>
<dt>{{jsxref("Number.NaN")}}</dt>
<dd>Special "<strong>N</strong>ot <strong>a</strong> <strong>N</strong>umber" value.</dd>
<dt>{{jsxref("Number.NEGATIVE_INFINITY")}}</dt>
<dd>Special value representing negative infinity. Returned on overflow.</dd>
<dt>{{jsxref("Number.POSITIVE_INFINITY")}}</dt>
<dd>Special value representing infinity. Returned on overflow.</dd>
<dt>{{jsxref("Number.prototype")}}</dt>
<dd>Allows the addition of properties to the <code>Number</code> object.</dd>
</dl>
<h2 id="Static_methods">Static methods</h2>
<dl>
<dt>{{jsxref("Number.isNaN()")}}</dt>
<dd>Determine whether the passed value is <code>NaN</code>.</dd>
<dt>{{jsxref("Number.isFinite()")}}</dt>
<dd>Determine whether the passed value is a finite number.</dd>
<dt>{{jsxref("Number.isInteger()")}}</dt>
<dd>Determine whether the passed value is an integer.</dd>
<dt>{{jsxref("Number.isSafeInteger()")}}</dt>
<dd>Determine whether the passed value is a safe integer (number between <code>-(2<sup>53</sup> - 1)</code> and <code>2<sup>53</sup> - 1</code>).</dd>
<dt>{{jsxref("Number.parseFloat()", "Number.parseFloat(<var>string</var>)")}}</dt>
<dd>This is the same as the global {{jsxref("parseFloat", "parseFloat()")}} function.</dd>
<dt>{{jsxref("Number.parseInt()", "Number.parseInt(<var>string</var>, [<var>radix</var>])")}}</dt>
<dd>This is the same as the global {{jsxref("parseInt", "parseInt()")}} function.</dd>
</dl>
<h2 id="Instance_methods">Instance methods</h2>
<dl>
<dt>{{jsxref("Number.prototype.toExponential()" ,"Number.prototype.toExponential(<var>fractionDigits</var>)")}}</dt>
<dd>Returns a string representing the number in exponential notation.</dd>
<dt>{{jsxref("Number.prototype.toFixed()", "Number.prototype.toFixed(<var>digits</var>)")}}</dt>
<dd>Returns a string representing the number in fixed-point notation.</dd>
<dt>{{jsxref("Number.prototype.toLocaleString()", "Number.prototype.toLocaleString([<var>locales</var> [, <var>options</var>]])")}}</dt>
<dd>Returns a string with a language sensitive representation of this number. Overrides the {{jsxref("Object.prototype.toLocaleString()")}} method.</dd>
<dt>{{jsxref("Number.prototype.toPrecision()", "Number.prototype.toPrecision(<var>precision</var>)")}}</dt>
<dd>Returns a string representing the number to a specified precision in fixed-point or exponential notation.</dd>
<dt>{{jsxref("Number.prototype.toString()", "Number.prototype.toString([<var>radix</var>])")}}</dt>
<dd>Returns a string representing the specified object in the specified <var>radix</var> ("base"). Overrides the {{jsxref("Object.prototype.toString()")}} method.</dd>
<dt>{{jsxref("Number.prototype.valueOf()")}}</dt>
<dd>Returns the primitive value of the specified object. Overrides the {{jsxref("Object.prototype.valueOf()")}} method.</dd>
</dl>
<h2 id="Examples">Examples</h2>
<h3 id="Using_the_Number_object_to_assign_values_to_numeric_variables">Using the Number object to assign values to numeric variables</h3>
<p>The following example uses the <code>Number</code> object's properties to assign values to several numeric variables:</p>
<pre class="brush: js notranslate">const biggestNum = Number.MAX_VALUE
const smallestNum = Number.MIN_VALUE
const infiniteNum = Number.POSITIVE_INFINITY
const negInfiniteNum = Number.NEGATIVE_INFINITY
const notANum = Number.NaN
</pre>
<h3 id="Integer_range_for_Number">Integer range for Number</h3>
<p>The following example shows the minimum and maximum integer values that can be represented as <code>Number</code> object. (More details on this are described in the ECMAScript standard, chapter <em><a href="https://tc39.github.io/ecma262/#sec-ecmascript-language-types-number-type">6.1.6 The Number Type</a>.</em>)</p>
<pre class="brush: js notranslate">const biggestInt = Number.MAX_SAFE_INTEGER // (<code>2<sup>53</sup> - 1</code>) => 9007199254740991
const smallestInt = Number.MIN_SAFE_INTEGER // -(<code>2<sup>53</sup> - 1</code>) => -9007199254740991</pre>
<p>When parsing data that has been serialized to JSON, integer values falling outside of this range can be expected to become corrupted when JSON parser coerces them to <code>Number</code> type.</p>
<p>A possible workaround is to use {{jsxref("String")}} instead.</p>
<p>Larger numbers can be represented using the {{jsxref("BigInt")}} type.</p>
<h3 id="Using_Number_to_convert_a_Date_object">Using Number to convert a Date object</h3>
<p>The following example converts the {{jsxref("Date")}} object to a numerical value using <code>Number</code> as a function:</p>
<pre class="brush: js notranslate">let d = new Date('December 17, 1995 03:24:00')
console.log(Number(d))
</pre>
<p>This logs <code>819199440000</code>.</p>
<h3 id="Convert_numeric_strings_and_null_to_numbers">Convert numeric strings and null to numbers</h3>
<pre class="brush: js notranslate" dir="rtl">Number('123') // 123
Number('123') === 123 /// true
Number('12.3') // 12.3
Number('12.00') // 12
Number('123e-1') // 12.3
Number('') // 0
Number(null) // 0
Number('0x11') // 17
Number('0b11') // 3
Number('0o11') // 9
Number('foo') // NaN
Number('100a') // NaN
Number('-Infinity') //-Infinity</pre>
<h2 id="Specifications">Specifications</h2>
<table class="standard-table">
<thead>
<tr>
<th scope="col">Specification</th>
</tr>
</thead>
<tbody>
<tr>
<td>{{SpecName('ESDraft', '#sec-number-objects', 'Number')}}</td>
</tr>
</tbody>
</table>
<h2 id="Browser_compatibility">Browser compatibility</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.Number")}}</p>
<h2 id="See_also">See also</h2>
<ul>
<li>{{jsxref("NaN")}}</li>
<li>{{jsxref("Arithmetic operators")}}</li>
<li>The {{jsxref("Math")}} global object</li>
<li>Integers with arbitrary precision: {{jsxref("BigInt")}}</li>
</ul>
|
