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    <title>DEV Community: Takamichi Oki</title>
    <description>The latest articles on DEV Community by Takamichi Oki (@michi0808).</description>
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      <title>React useContext for Beginners: Passing Data Without Props</title>
      <dc:creator>Takamichi Oki</dc:creator>
      <pubDate>Wed, 17 Dec 2025 19:26:36 +0000</pubDate>
      <link>https://dev.to/michi0808/react-usecontext-for-beginners-passing-data-without-props-42lg</link>
      <guid>https://dev.to/michi0808/react-usecontext-for-beginners-passing-data-without-props-42lg</guid>
      <description>&lt;h2&gt;
  
  
  Introduction
&lt;/h2&gt;

&lt;p&gt;&lt;code&gt;props&lt;/code&gt; are the basic way to pass values from a parent component to a child component. But as your component tree gets deeper, &lt;code&gt;useContext&lt;/code&gt; becomes a better option.&lt;/p&gt;

&lt;p&gt;In this article, I’ll walk through how to use &lt;code&gt;useContext&lt;/code&gt; and explain the difference between using &lt;code&gt;props&lt;/code&gt; and using context.&lt;/p&gt;

&lt;h2&gt;
  
  
  What is &lt;code&gt;useContext&lt;/code&gt;?
&lt;/h2&gt;

&lt;p&gt;&lt;code&gt;useContext&lt;/code&gt; is a React Hook that lets you share values between components without passing &lt;code&gt;props&lt;/code&gt; through every level of the component tree.&lt;/p&gt;

&lt;p&gt;In other words, you can use context to pass data down the tree instead of prop drilling.&lt;/p&gt;

&lt;h2&gt;
  
  
  Props: the Problem
&lt;/h2&gt;

&lt;p&gt;Before diving into &lt;code&gt;useContext&lt;/code&gt;, let’s look at the problems you can run into when you rely on props, especially as your component tree grows.&lt;/p&gt;

&lt;p&gt;Here’s an example app that uses props:&lt;/p&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Frbcthm7a026obbcsd8hp.png" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Frbcthm7a026obbcsd8hp.png" alt=" " width="642" height="227"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;On this screen, you can choose your preferred language.&lt;/p&gt;

&lt;p&gt;Here’s the source code for the app:&lt;/p&gt;

&lt;h4&gt;
  
  
  &lt;code&gt;App.jsx&lt;/code&gt;
&lt;/h4&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;useState&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;react&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;LangHeader&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./components/LangHeader&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;App&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="nx"&gt;lang&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;setLang&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;useState&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;English&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;toggleLang&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;newLang&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;target&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;value&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nf"&gt;setLang&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;newLang&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;LangHeader&lt;/span&gt; &lt;span class="na"&gt;lang&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;lang&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt; &lt;span class="na"&gt;toggleLang&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;toggleLang&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt; &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="nx"&gt;App&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h4&gt;
  
  
  &lt;code&gt;LangHeader.jsx&lt;/code&gt;
&lt;/h4&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;React&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;react&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;LangContent&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./LangContent&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;LangHeader&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="nx"&gt;lang&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;toggleLang&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;LangHeader&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;LangContent&lt;/span&gt; &lt;span class="na"&gt;lang&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;lang&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt; &lt;span class="na"&gt;toggleLang&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;toggleLang&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt; &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;/&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h4&gt;
  
  
  &lt;code&gt;LangContent.jsx&lt;/code&gt;
&lt;/h4&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;React&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;react&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;LangContent&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="nx"&gt;lang&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;toggleLang&lt;/span&gt; &lt;span class="p"&gt;})&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;LANGUAGES&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;English&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;German&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Japanese&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;];&lt;/span&gt;

  &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;LangContent&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;p&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;current setting is: &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;lang&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;p&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;LANGUAGES&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;l&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;React&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;Fragment&lt;/span&gt; &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;l&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
          &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;label&lt;/span&gt; &lt;span class="na"&gt;htmlFor&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;l&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;l&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;label&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
          &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;input&lt;/span&gt; &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;l&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
          &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;'lang'&lt;/span&gt;
          &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;'radio'&lt;/span&gt;
          &lt;span class="na"&gt;value&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;l&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
          &lt;span class="na"&gt;onChange&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;toggleLang&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
          &lt;span class="na"&gt;checked&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;lang&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="nx"&gt;l&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
            &lt;span class="p"&gt;&amp;gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;input&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nc"&gt;React&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;Fragment&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="p"&gt;})&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;/&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;ul&gt;
&lt;li&gt;
&lt;code&gt;App&lt;/code&gt; is the top-level component. It keeps the selected language in state and defines the handler to switch languages.&lt;/li&gt;
&lt;li&gt;
&lt;code&gt;LangHeader&lt;/code&gt; receives lang and toggleLang as &lt;code&gt;props&lt;/code&gt; from &lt;code&gt;App&lt;/code&gt;, then passes them down to its child component.&lt;/li&gt;
&lt;li&gt;
&lt;code&gt;LangContent&lt;/code&gt; renders the UI: it shows the current setting and the radio buttons, using the &lt;code&gt;props&lt;/code&gt; it receives.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;As you can see in the source code, &lt;code&gt;LangHeader&lt;/code&gt; receives &lt;code&gt;props&lt;/code&gt; only to pass them down to its child. When a deeply nested component needs those &lt;code&gt;props&lt;/code&gt;, every component in between has to forward them, even if they don’t use them themselves.&lt;/p&gt;

&lt;p&gt;This is often called prop drilling. It’s basically like a bucket brigade.&lt;/p&gt;

&lt;p&gt;In this example the component tree is shallow, so it’s not a big deal. But as the tree grows, prop drilling becomes harder to maintain and easier to break.&lt;/p&gt;

&lt;h2&gt;
  
  
  The Basics of &lt;code&gt;useContext&lt;/code&gt;
&lt;/h2&gt;

&lt;p&gt;&lt;code&gt;useContext&lt;/code&gt; can solve this problem. With context, you can share values without passing props through every intermediate component, almost like the values “skip” levels in the component tree.&lt;/p&gt;

&lt;p&gt;The flow is simple:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Create a context&lt;/li&gt;
&lt;li&gt;Provide a context value&lt;/li&gt;
&lt;li&gt;Consume the context in a component (&lt;code&gt;useContext&lt;/code&gt;)&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Let’s go through each step one by one.&lt;/p&gt;

&lt;h2&gt;
  
  
  Create a Context
&lt;/h2&gt;

&lt;p&gt;First, you need to create a context object using &lt;code&gt;createContext&lt;/code&gt;.&lt;/p&gt;

&lt;p&gt;The key points are:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Call &lt;code&gt;createContext()&lt;/code&gt; outside of any component (so it’s created once, not on every render).&lt;/li&gt;
&lt;li&gt;Pass a default value as the argument. This value is used when there is no matching Provider above in the tree.
&lt;/li&gt;
&lt;/ul&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;createContext&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;react&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;AppContext&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;createContext&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;If you plan to share multiple values (e.g., both the current language and a setter/handler), it’s common to use an object as the default value:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;createContext&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;react&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;AppContext&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;createContext&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="na"&gt;value&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="na"&gt;setValue&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{},&lt;/span&gt;
&lt;span class="p"&gt;});&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Provide a Context Value
&lt;/h2&gt;

&lt;p&gt;A Provider is how you supply a context value to components below it.&lt;/p&gt;

&lt;p&gt;To use it, wrap the part of your component tree that should have access to the value with &lt;code&gt;&amp;lt;YourContext.Provider&amp;gt;&lt;/code&gt;, then pass the value via the &lt;code&gt;value&lt;/code&gt; prop.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;useState&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;react&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;AppContext&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;./AppContext&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;App&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="nx"&gt;value&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;setValue&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;useState&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;A&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;handleChange&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="nf"&gt;setValue&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;target&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;value&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

  &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;AppContext&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;Provider&lt;/span&gt; &lt;span class="na"&gt;value&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;value&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;handleChange&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;Child&lt;/span&gt; &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nc"&gt;AppContext&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;Provider&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Notes:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;The value you pass can be a single value (e.g. &lt;code&gt;value={value}&lt;/code&gt;) or an object (e.g. &lt;code&gt;value={{ value, handleChange }}&lt;/code&gt;), depending on what you want to share.&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Consume the Context in a Component
&lt;/h2&gt;

&lt;p&gt;To read a context value inside a component, use the &lt;code&gt;useContext&lt;/code&gt; Hook.&lt;/p&gt;

&lt;p&gt;Pass the context object (the one created by &lt;code&gt;createContext&lt;/code&gt;) as the argument.&lt;br&gt;
&lt;code&gt;useContext&lt;/code&gt; returns whatever you provided via the nearest &lt;code&gt;&amp;lt;Provider value={...}&amp;gt;&lt;/code&gt; above in the tree.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;useContext&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;react&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;AppContext&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;./AppContext&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;Child&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;value&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;handleChange&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;useContext&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;AppContext&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

  &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;p&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;Current value: &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;value&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;p&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;

      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;label&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;input&lt;/span&gt; &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"radio"&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"demo"&lt;/span&gt; &lt;span class="na"&gt;value&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"A"&lt;/span&gt; &lt;span class="na"&gt;onChange&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;handleChange&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt; &lt;span class="na"&gt;checked&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;value&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;A&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt; &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
        A
      &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;label&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;

      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;label&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;input&lt;/span&gt; &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"radio"&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"demo"&lt;/span&gt; &lt;span class="na"&gt;value&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"B"&lt;/span&gt; &lt;span class="na"&gt;onChange&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;handleChange&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt; &lt;span class="na"&gt;checked&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;value&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;B&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt; &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
        B
      &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;label&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;/&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Refactoring the App to use Context
&lt;/h2&gt;

&lt;p&gt;Now, let’s refactor the example app to use context.&lt;/p&gt;

&lt;h4&gt;
  
  
  &lt;code&gt;generateContext.js&lt;/code&gt;
&lt;/h4&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;createContext&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;react&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;LangContext&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;createContext&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;English&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;First, create a context and export it so you can import it later when you provide the value with a &lt;code&gt;Provider&lt;/code&gt;.&lt;/p&gt;

&lt;h4&gt;
  
  
  &lt;code&gt;App.jsx&lt;/code&gt;
&lt;/h4&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;useState&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;react&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;LangHeader&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./components/LangHeader&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;LangContext&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./generateContext&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;App&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="nx"&gt;lang&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;setLang&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;useState&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;English&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;toggleLang&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;newLang&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;e&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;target&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;value&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="nf"&gt;setLang&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;newLang&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="c1"&gt;// Wrap the component tree with the Provider&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;LangContext&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;Provider&lt;/span&gt; &lt;span class="na"&gt;value&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;lang&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;toggleLang&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
      &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="cm"&gt;/* No need to pass props down anymore. */&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;LangHeader&lt;/span&gt; &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nc"&gt;LangContext&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;Provider&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="nx"&gt;App&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Next, import the context you created earlier and wrap your component tree with its &lt;code&gt;Provider&lt;/code&gt;.&lt;/p&gt;

&lt;p&gt;You can think of this as setting up a “channel” that delivers the values to any components below that need them.&lt;/p&gt;

&lt;h4&gt;
  
  
  &lt;code&gt;LangHeader.jsx&lt;/code&gt;
&lt;/h4&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;React&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;react&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;LangContent&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./LangContent&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;LangHeader&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;LangHeader&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;LangContent&lt;/span&gt; &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;/&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;As you can see, &lt;code&gt;LangHeader&lt;/code&gt; (an intermediate component) no longer needs to receive &lt;code&gt;props&lt;/code&gt; just to pass them down.&lt;/p&gt;

&lt;h4&gt;
  
  
  &lt;code&gt;LangContent.jsx&lt;/code&gt;
&lt;/h4&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight jsx"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;React&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;react&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;useContext&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;react&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;LangContext&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;../generateContext&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;LangContent&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;  &lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;LANGUAGES&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;English&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;German&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Japanese&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;];&lt;/span&gt;

  &lt;span class="c1"&gt;// Now you can read the values provided by the nearest Provider.&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;lang&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;toggleLang&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;useContext&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;LangContext&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

  &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;LangContent&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;p&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;current setting is: &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;lang&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;p&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;LANGUAGES&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;map&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;l&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nc"&gt;React&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;Fragment&lt;/span&gt; &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;l&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
          &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;label&lt;/span&gt; &lt;span class="na"&gt;htmlFor&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;l&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;l&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;label&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
          &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;input&lt;/span&gt; &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;l&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
          &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;'lang'&lt;/span&gt;
          &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;'radio'&lt;/span&gt;
          &lt;span class="na"&gt;value&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;l&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
          &lt;span class="na"&gt;onChange&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;toggleLang&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
          &lt;span class="na"&gt;checked&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;lang&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="nx"&gt;l&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
            &lt;span class="p"&gt;&amp;gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;input&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nc"&gt;React&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nc"&gt;Fragment&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="p"&gt;})&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;/&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;)&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Finally, consume the value in a deeply nested component and use it directly.&lt;/p&gt;

&lt;p&gt;With prop drilling gone, the app still behaves exactly the same as it did before the refactor.&lt;/p&gt;

&lt;h2&gt;
  
  
  Summary
&lt;/h2&gt;

&lt;p&gt;Context can feel a bit like a global variable, because it lets you share values between components without manually passing &lt;code&gt;props&lt;/code&gt; through every level.&lt;/p&gt;

&lt;p&gt;The key point is that the Provider’s value often includes &lt;code&gt;state&lt;/code&gt;. When that &lt;code&gt;state&lt;/code&gt; updates, any components that consume the context will re-render, even if they’re far away in the component tree.&lt;/p&gt;

</description>
      <category>react</category>
      <category>javascript</category>
      <category>beginners</category>
      <category>coding</category>
    </item>
  </channel>
</rss>
