Creating a Simple Node.js Hello World App

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Introduction

Node.js is a powerful JavaScript runtime that allows you to build fast and scalable applications. In this tutorial, we’ll create a simple Hello, World! application using Node.js.

Step 1: Install Node.js

Download and install Node.js from the official website: https://nodejs.org/.
Verify the installation:bashCopy code

<span class="line"><span style="color: #D8DEE9FF">node </span><span style="color: #81A1C1">-</span><span style="color: #D8DEE9FF">v</span></span>
<span class="line"><span style="color: #D8DEE9FF">npm </span><span style="color: #81A1C1">-</span><span style="color: #D8DEE9FF">v</span></span>

Step 2: Create the Node.js Application

Create a new directory for your project:

<span class="line"><span style="color: #D8DEE9FF">mkdir hello</span><span style="color: #81A1C1">-</span><span style="color: #D8DEE9FF">node</span></span>
<span class="line"><span style="color: #D8DEE9FF">cd hello</span><span style="color: #81A1C1">-</span><span style="color: #D8DEE9FF">node</span></span>
<span class="line"></span>
<span class="line"><span style="color: #D8DEE9FF"># </span><span style="color: #8FBCBB">Initialize</span><span style="color: #D8DEE9FF"> a </span><span style="color: #81A1C1">new</span><span style="color: #D8DEE9FF"> Node</span><span style="color: #ECEFF4">.</span><span style="color: #D8DEE9">js</span><span style="color: #D8DEE9FF"> project</span><span style="color: #81A1C1">:</span></span>
<span class="line"><span style="color: #D8DEE9FF">npm init </span><span style="color: #81A1C1">-</span><span style="color: #D8DEE9FF">y</span></span>
<span class="line"></span>
<span class="line"><span style="color: #D8DEE9FF"># </span><span style="color: #8FBCBB">Create</span><span style="color: #D8DEE9FF"> a </span><span style="color: #81A1C1">new</span><span style="color: #D8DEE9FF"> file named app</span><span style="color: #ECEFF4">.</span><span style="color: #D8DEE9">js</span><span style="color: #81A1C1">:</span></span>
<span class="line"><span style="color: #D8DEE9FF">touch </span><span style="color: #D8DEE9">app</span><span style="color: #ECEFF4">.</span><span style="color: #D8DEE9">js</span></span>

Node.js

<span class="line"><span style="color: #81A1C1">const</span><span style="color: #D8DEE9FF"> http </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #88C0D0">require</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">http</span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">)</span><span style="color: #81A1C1">;</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88">// Create a server</span></span>
<span class="line"><span style="color: #81A1C1">const</span><span style="color: #D8DEE9FF"> server </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #D8DEE9">http</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">createServer</span><span style="color: #ECEFF4">((</span><span style="color: #D8DEE9FF">req</span><span style="color: #ECEFF4">,</span><span style="color: #D8DEE9FF"> res</span><span style="color: #ECEFF4">)</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">=></span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">{</span></span>
<span class="line"><span style="color: #D8DEE9FF">  </span><span style="color: #D8DEE9">res</span><span style="color: #ECEFF4">.</span><span style="color: #D8DEE9">statusCode</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #B48EAD">200</span><span style="color: #81A1C1">;</span><span style="color: #D8DEE9FF"> </span><span style="color: #616E88">// HTTP status for OK</span></span>
<span class="line"><span style="color: #D8DEE9FF">  </span><span style="color: #D8DEE9">res</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">setHeader</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">Content-Type</span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">,</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">text/plain</span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">)</span><span style="color: #81A1C1">;</span></span>
<span class="line"><span style="color: #D8DEE9FF">  </span><span style="color: #D8DEE9">res</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">end</span><span style="color: #ECEFF4">(</span><span style="color: #ECEFF4">'</span><span style="color: #A3BE8C">Hello, World!</span><span style="color: #ECEFF4">'</span><span style="color: #ECEFF4">)</span><span style="color: #81A1C1">;</span></span>
<span class="line"><span style="color: #ECEFF4">})</span><span style="color: #81A1C1">;</span></span>
<span class="line"></span>
<span class="line"><span style="color: #616E88">// Start the server</span></span>
<span class="line"><span style="color: #81A1C1">const</span><span style="color: #D8DEE9FF"> PORT </span><span style="color: #81A1C1">=</span><span style="color: #D8DEE9FF"> </span><span style="color: #B48EAD">3000</span><span style="color: #81A1C1">;</span></span>
<span class="line"><span style="color: #D8DEE9">server</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">listen</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">PORT</span><span style="color: #ECEFF4">,</span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">()</span><span style="color: #D8DEE9FF"> </span><span style="color: #81A1C1">=></span><span style="color: #D8DEE9FF"> </span><span style="color: #ECEFF4">{</span></span>
<span class="line"><span style="color: #D8DEE9FF">  </span><span style="color: #D8DEE9">console</span><span style="color: #ECEFF4">.</span><span style="color: #88C0D0">log</span><span style="color: #ECEFF4">(</span><span style="color: #D8DEE9FF">`</span><span style="color: #8FBCBB">Server</span><span style="color: #D8DEE9FF"> running at </span><span style="color: #D8DEE9">http</span><span style="color: #81A1C1">:</span><span style="color: #616E88">//localhost:${PORT}/`);</span></span>
<span class="line"><span style="color: #D8DEE9FF">}</span><span style="color: #ECEFF4">)</span><span style="color: #81A1C1">;</span></span>
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Step 3: Run the Application

<span class="line"><span style="color: #D8DEE9FF">node </span><span style="color: #D8DEE9">app</span><span style="color: #ECEFF4">.</span><span style="color: #D8DEE9">js</span></span>

Step 4: Folder Structure

Your folder should look like this:

<span class="line"><span style="color: #D8DEE9FF">hello</span><span style="color: #81A1C1">-</span><span style="color: #D8DEE9FF">node</span><span style="color: #81A1C1">/</span></span>
<span class="line"><span style="color: #D8DEE9FF">├── </span><span style="color: #D8DEE9">app</span><span style="color: #ECEFF4">.</span><span style="color: #D8DEE9">js</span></span>
<span class="line"><span style="color: #D8DEE9FF">└── </span><span style="color: #81A1C1">package</span><span style="color: #ECEFF4">.</span><span style="color: #8FBCBB">json</span></span>

Conclusion

That’s it! You’ve created your first Node.js Hello, World! application. From here, you can expand your project by adding features like APIs, database connections, or front-end integrations.

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