| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="A type that can be used to index into a `serde_json::Value`."><meta name="keywords" content="rust, rustlang, rust-lang, Index"><title>Index in serde_json::value - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="sidebar-items.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc trait"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle">☰</button><a class="sidebar-logo" href="../../serde_json/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../../serde_json/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">Index</a></h2><div class="sidebar-elems"><section><h3><a href="#foreign-impls">Implementations on Foreign Types</a></h3><ul class="block"><li><a href="#impl-Index-for-%26%27a%20T">&'a T</a></li><li><a href="#impl-Index-for-String">String</a></li><li><a href="#impl-Index-for-str">str</a></li><li><a href="#impl-Index-for-usize">usize</a></li></ul><h3><a href="#implementors">Implementors</a></h3></section><h2><a href="index.html">In serde_json::value</a></h2></div></nav><main><div class="width-limiter"><nav class="sub"><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="main-heading"><h1 class="fqn">Trait <a href="../index.html">serde_json</a>::<wbr><a href="index.html">value</a>::<wbr><a class="trait" href="#">Index</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../../clipboard.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="srclink" href="../../src/serde_json/value/index.rs.html#37-52">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><div class="item-decl"><pre class="rust trait"><code>pub trait Index: Sealed { }</code></pre></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>A type that can be used to index into a <code>serde_json::Value</code>.</p> |
| <p>The <a href="../enum.Value.html#method.get"><code>get</code></a> and <a href="../enum.Value.html#method.get_mut"><code>get_mut</code></a> methods of <code>Value</code> accept any type that |
| implements <code>Index</code>, as does the <a href="../enum.Value.html#impl-Index%3CI%3E">square-bracket indexing operator</a>. This |
| trait is implemented for strings which are used as the index into a JSON |
| map, and for <code>usize</code> which is used as the index into a JSON array.</p> |
| <p>This trait is sealed and cannot be implemented for types outside of |
| <code>serde_json</code>.</p> |
| <h2 id="examples"><a href="#examples">Examples</a></h2> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">let </span>data = <span class="macro">json!</span>({ <span class="string">"inner"</span>: [<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>] }); |
| |
| <span class="comment">// Data is a JSON map so it can be indexed with a string. |
| </span><span class="kw">let </span>inner = <span class="kw-2">&</span>data[<span class="string">"inner"</span>]; |
| |
| <span class="comment">// Inner is a JSON array so it can be indexed with an integer. |
| </span><span class="kw">let </span>first = <span class="kw-2">&</span>inner[<span class="number">0</span>]; |
| |
| <span class="macro">assert_eq!</span>(first, <span class="number">1</span>);</code></pre></div> |
| </div></details><h2 id="foreign-impls" class="small-section-header">Implementations on Foreign Types<a href="#foreign-impls" class="anchor"></a></h2><section id="impl-Index-for-usize" class="impl has-srclink"><a class="srclink rightside" href="../../src/serde_json/value/index.rs.html#54-81">source</a><a href="#impl-Index-for-usize" class="anchor"></a><h3 class="code-header">impl <a class="trait" href="trait.Index.html" title="trait serde_json::value::Index">Index</a> for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.usize.html">usize</a></h3></section><section id="impl-Index-for-str" class="impl has-srclink"><a class="srclink rightside" href="../../src/serde_json/value/index.rs.html#83-105">source</a><a href="#impl-Index-for-str" class="anchor"></a><h3 class="code-header">impl <a class="trait" href="trait.Index.html" title="trait serde_json::value::Index">Index</a> for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a></h3></section><section id="impl-Index-for-String" class="impl has-srclink"><a class="srclink rightside" href="../../src/serde_json/value/index.rs.html#107-117">source</a><a href="#impl-Index-for-String" class="anchor"></a><h3 class="code-header">impl <a class="trait" href="trait.Index.html" title="trait serde_json::value::Index">Index</a> for <a class="struct" href="https://doc.rust-lang.org/nightly/alloc/string/struct.String.html" title="struct alloc::string::String">String</a></h3></section><section id="impl-Index-for-%26%27a%20T" class="impl has-srclink"><a class="srclink rightside" href="../../src/serde_json/value/index.rs.html#119-132">source</a><a href="#impl-Index-for-%26%27a%20T" class="anchor"></a><h3 class="code-header">impl<'a, T> <a class="trait" href="trait.Index.html" title="trait serde_json::value::Index">Index</a> for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&'a </a>T<span class="where fmt-newline">where<br> T: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="trait.Index.html" title="trait serde_json::value::Index">Index</a>,</span></h3></section><h2 id="implementors" class="small-section-header">Implementors<a href="#implementors" class="anchor"></a></h2><div id="implementors-list"></div><script src="../../implementors/serde_json/value/index/trait.Index.js" data-ignore-extern-crates="std,alloc" async></script></section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="serde_json" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
