This content originally appeared on DEV Community and was authored by Adetola Hannah
In the world of machine learning and artificial intelligence, classification tasks play a crucial role in sorting and analyzing data. One such task is number classification, which involves determining whether a given number is positive, negative, or zero. In this blog post, we'll explore how to build a simple Number Classification API using Node.js.
Introduction
The Number Classification API is a lightweight RESTful service built with Node.js and Express.js. It takes a number as input and returns its classification: positive, negative, or zero. This API is useful for educational purposes, small-scale applications, and learning the basics of API development.
Setting Up the Project
To get started, clone the repository from GitHub:
$ git clone https://github.com/ajalaadetola/number-classification-api.git
$ cd number-classification-api
Next, install the required dependencies:
$ npm install
Understanding the Code
Let's break down the core logic of the API. The main entry point of the application is index.js. Here’s a look at its key components:
1. Importing Dependencies
const express = require('express');
const app = express();
We use Express.js to set up a simple web server.
2. Creating the Classification Logic
// API Endpoint
app.get("/api/classify-number", async (req, res) => {
const { number } = req.query;
// Validate input: Ensure the number is provided and valid
if (!number || isNaN(number)) {
return res.status(400).json({
number, // ✅ Include the invalid input as it was received
error: "Invalid number"
});
}
const num = Number(number); // Convert to a valid number
const properties = [];
if (isArmstrong(num)) properties.push("armstrong");
properties.push(num % 2 === 0 ? "even" : "odd");
const funFact = await getFunFact(num);
// ✅ Fix: Ensure digit_sum is numeric, even for negative numbers
const digitSum = Math.abs(num)
.toString()
.split("")
.filter(char => !isNaN(char)) // Remove non-numeric characters like "-"
.reduce((sum, digit) => sum + parseInt(digit), 0);
res.json({
number: num,
is_prime: isPrime(num),
is_perfect: isPerfect(num),
properties,
digit_sum: digitSum,
fun_fact: funFact
});
});
3. Running the Server
const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
console.log(`Server running on port ${PORT}`);
});
This sets up the server to listen on port 3000 or an environment-specified port.
Testing the API
You can test the API locally using Postman or your web browser. Start the server:
$ node index.js
Then, open your browser and enter the following URL:
http://localhost:3000/api/classify-number?number=10
You should receive a response like:
{
"digit_sum": 11,
"fun_fact": "371 is a narcissistic number.",
"is_perfect": false,
"is_prime": false,
"number": 371,
"properties": [
"armstrong",
"odd"
]
}
Deploying the API on Render
You can deploy this API using Render, a cloud hosting platform that provides seamless deployment for Node.js applications.
Steps to Deploy on Render:
- Create an account on Render.
- Click New Web Service and connect your GitHub repository.
- Select the repository
number-classification-api. - Set the runtime environment to Node.js.
- Configure the start command as:
node index.js
- Click Deploy and wait for the build to complete.
Once deployed, Render will provide a public URL where your API can be accessed.
Conclusion
This simple Number Classification API demonstrates how to build and deploy a basic REST API using Node.js and Express.js. By understanding the fundamentals of request handling and data validation, you can extend this project further—perhaps by integrating a machine learning model for more complex classifications.
Check out the full code on GitHub: Number Classification API 🚀.
Happy coding! 🎉
This content originally appeared on DEV Community and was authored by Adetola Hannah
Adetola Hannah | Sciencx (2025-02-24T21:00:38+00:00) Deploying a Simple Number Classification API with Node.js and Render. Retrieved from https://www.scien.cx/2025/02/24/deploying-a-simple-number-classification-api-with-node-js-and-render/
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