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<h2>Table of Contents</h2>
<ul>
<li><span class="stability_2"><a href="#querystring_query_string">Query String</a></span><ul>
<li><span class="stability_undefined"><a href="#querystring_querystring_escape_str">querystring.escape(str)</a></span></li>
<li><span class="stability_undefined"><a href="#querystring_querystring_parse_str_sep_eq_options">querystring.parse(str[, sep[, eq[, options]]])</a></span></li>
<li><span class="stability_undefined"><a href="#querystring_querystring_stringify_obj_sep_eq_options">querystring.stringify(obj[, sep[, eq[, options]]])</a></span></li>
<li><span class="stability_undefined"><a href="#querystring_querystring_unescape_str">querystring.unescape(str)</a></span></li>
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<h1>Query String<span><a class="mark" href="#querystring_query_string"id="querystring_query_string">#</a></span></h1>
<!--introduced_in=v0.10.0-->
<div class="api_stability api_stability_2"><a href="documentation.html#documentation_stability_index">Stability: 2</a> - Stable</div><!--name=querystring-->
<p>The <code>querystring</code> module provides utilities for parsing and formatting URL
query strings. It can be accessed using:</p>
<pre><code class="lang-js">const querystring = require('querystring');
</code></pre>
<h2>querystring.escape(str)<span><a class="mark" href="#querystring_querystring_escape_str"id="querystring_querystring_escape_str">#</a></span></h2>
<div class="api_metadata">
<span>Added in: v0.1.25</span>
</div><ul>
<li><code>str</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li>
</ul>
<p>The <code>querystring.escape()</code> method performs URL percent-encoding on the given
<code>str</code> in a manner that is optimized for the specific requirements of URL
query strings.</p>
<p>The <code>querystring.escape()</code> method is used by <code>querystring.stringify()</code> and is
generally not expected to be used directly. It is exported primarily to allow
application code to provide a replacement percent-encoding implementation if
necessary by assigning <code>querystring.escape</code> to an alternative function.</p>
<h2>querystring.parse(str[, sep[, eq[, options]]])<span><a class="mark" href="#querystring_querystring_parse_str_sep_eq_options"id="querystring_querystring_parse_str_sep_eq_options">#</a></span></h2>
<div class="api_metadata">
<span>Added in: v0.1.25</span>
</div><ul>
<li><code>str</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> The URL query string to parse</li>
<li><code>sep</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> The substring used to delimit key and value pairs in the
query string. Defaults to <code>'&'</code>.</li>
<li><code>eq</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a>. The substring used to delimit keys and values in the
query string. Defaults to <code>'='</code>.</li>
<li><code>options</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a><ul>
<li><code>decodeURIComponent</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> The function to use when decoding
percent-encoded characters in the query string. Defaults to
<code>querystring.unescape()</code>.</li>
<li><code>maxKeys</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a> Specifies the maximum number of keys to parse.
Defaults to <code>1000</code>. Specify <code>0</code> to remove key counting limitations.</li>
</ul>
</li>
</ul>
<p>The <code>querystring.parse()</code> method parses a URL query string (<code>str</code>) into a
collection of key and value pairs.</p>
<p>For example, the query string <code>'foo=bar&abc=xyz&abc=123'</code> is parsed into:</p>
<!-- eslint-skip -->
<pre><code class="lang-js">{
foo: 'bar',
abc: ['xyz', '123']
}
</code></pre>
<p><em>Note</em>: The object returned by the <code>querystring.parse()</code> method <em>does not</em>
prototypically extend from the JavaScript <code>Object</code>. This means that the
typical <code>Object</code> methods such as <code>obj.toString()</code>, <code>obj.hasOwnProperty()</code>,
and others are not defined and <em>will not work</em>.</p>
<p>By default, percent-encoded characters within the query string will be assumed
to use UTF-8 encoding. If an alternative character encoding is used, then an
alternative <code>decodeURIComponent</code> option will need to be specified as illustrated
in the following example:</p>
<pre><code class="lang-js">// Assuming gbkDecodeURIComponent function already exists...
querystring.parse('w=%D6%D0%CE%C4&foo=bar', null, null,
{ decodeURIComponent: gbkDecodeURIComponent });
</code></pre>
<h2>querystring.stringify(obj[, sep[, eq[, options]]])<span><a class="mark" href="#querystring_querystring_stringify_obj_sep_eq_options"id="querystring_querystring_stringify_obj_sep_eq_options">#</a></span></h2>
<div class="api_metadata">
<span>Added in: v0.1.25</span>
</div><ul>
<li><code>obj</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object" class="type"><Object></a> The object to serialize into a URL query string</li>
<li><code>sep</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> The substring used to delimit key and value pairs in the
query string. Defaults to <code>'&'</code>.</li>
<li><code>eq</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a>. The substring used to delimit keys and values in the
query string. Defaults to <code>'='</code>.</li>
<li><code>options</code><ul>
<li><code>encodeURIComponent</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function" class="type"><Function></a> The function to use when converting
URL-unsafe characters to percent-encoding in the query string. Defaults to
<code>querystring.escape()</code>.</li>
</ul>
</li>
</ul>
<p>The <code>querystring.stringify()</code> method produces a URL query string from a
given <code>obj</code> by iterating through the object's "own properties".</p>
<p>It serializes the following types of values passed in <code>obj</code>:
<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string[]></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type" class="type"><number[]></a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type" class="type"><boolean[]></a>
Any other input values will be coerced to empty strings.</p>
<p>For example:</p>
<pre><code class="lang-js">querystring.stringify({ foo: 'bar', baz: ['qux', 'quux'], corge: '' });
// returns 'foo=bar&baz=qux&baz=quux&corge='
querystring.stringify({ foo: 'bar', baz: 'qux' }, ';', ':');
// returns 'foo:bar;baz:qux'
</code></pre>
<p>By default, characters requiring percent-encoding within the query string will
be encoded as UTF-8. If an alternative encoding is required, then an alternative
<code>encodeURIComponent</code> option will need to be specified as illustrated in the
following example:</p>
<pre><code class="lang-js">// Assuming gbkEncodeURIComponent function already exists,
querystring.stringify({ w: '中文', foo: 'bar' }, null, null,
{ encodeURIComponent: gbkEncodeURIComponent });
</code></pre>
<h2>querystring.unescape(str)<span><a class="mark" href="#querystring_querystring_unescape_str"id="querystring_querystring_unescape_str">#</a></span></h2>
<div class="api_metadata">
<span>Added in: v0.1.25</span>
</div><ul>
<li><code>str</code> <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type" class="type"><string></a></li>
</ul>
<p>The <code>querystring.unescape()</code> method performs decoding of URL percent-encoded
characters on the given <code>str</code>.</p>
<p>The <code>querystring.unescape()</code> method is used by <code>querystring.parse()</code> and is
generally not expected to be used directly. It is exported primarily to allow
application code to provide a replacement decoding implementation if
necessary by assigning <code>querystring.unescape</code> to an alternative function.</p>
<p>By default, the <code>querystring.unescape()</code> method will attempt to use the
JavaScript built-in <code>decodeURIComponent()</code> method to decode. If that fails,
a safer equivalent that does not throw on malformed URLs will be used.</p>
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