Building an API server is an essential skill in modern web development. In particular, by combining Node.js and Express, you can build an efficient and scalable API in a short time. In this article, we will explain how to build an API server using Node.js step by step with practical code examples. We will explain carefully in terms that even elementary school students can understand, so that even intermediate developers can easily understand.
Introduction to Node.js and Express
Node.js is a runtime environment for executing JavaScript server-side. It achieves high performance through asynchronous I/O and event-driven architecture. Express is a lightweight web application framework for Node.js that makes it easy to manage routing and middleware.
Building a development environment
Step 1: Install Node.js and npm
Download and install Node.js from the official website (https://nodejs.org/ja). npm is included in Node.js.
Step 2: Initializing the Project
1 | |
This will create a package.json file to help you manage your project dependencies.
Step 3: Install Required Packages
1 | |
Creating a basic API endpoint
Create an index.js file and add the following code to it.
1 | '/' |
This code sets up a basic Express server and returns a message when the root endpoint is accessed.
Implementing CRUD Operations
In an API server, the important operations are to create, read, update, and delete data.
Example data
As an example of handling simple user data, we will use the following structure:
1 | } ]; |
Read (Get all users)
1 | |
Create
1 | |
Update (update user information)
1 | ); } }); |
Delete
1 | ( |
Security measures and best practices
When publishing an API server, it is important to take the following security measures:
• Input Validation: Validates user input and prevents the processing of invalid data.
• Authentication and Authorization: Uses JWT (JSON Web Token) and other methods to authenticate users and control access.
• Error Handling: Ensures that an appropriate response is returned even if an unexpected error occurs.
These measures help make our API servers more secure and reliable.
summary
In this article, we explained how to build an API server using Node.js and Express. We covered practical content from creating basic endpoints to implementing CRUD operations and security measures. Use this knowledge to try developing a more advanced API server.
English 
Japanese