NodeJS Express

ExpressJS

Express JS is a Node.js framework designed to build APIs that facilitate communication through HTTP requests and responses. One of the remarkable things about Express is that it gives developers complete control over the requests and responses that are associated with each of its app’s methods.

Let's start writing code and initializing the JavaScript project.

1. Create a New Terminal
   

2. Run npm init in your terminal for initializing your JavaScript project

3. After you run the npm init command, it will ask you about the package name which is the name of your project. (if you don't want to name your project you just press enter to skip, and it will name the project as a name that you see in the parenthesis).

    

   
   • In the version, you can specify the version of the project, If you don't want to specify the version, you just press Enter to skip this, it will set version 1.0.0 as default. 👇🏻
     

   

   • The description is just a description of your project, If you don't want to add a description, you just press Enter to skip this. 👇🏻

   

   • The entry point is the file from which execution starts. It depends on the project configuration and run time environment of the technology we are using.
   • Examples: For a node.js project index.js is used to initialize the app and glue everything together.

   

   • For the entry point, we will use index.js file as a main file, press Enter to skip this, and use the index.js as a default. 👆🏻
   • Skip the test command 👇🏻

   

   • For the git repository, you just leave it blank.

   

   • For the keywords, you just leave it blank.

   

   • The author is just the name of the owner of the project, you can leave it blank if you don't want to fill in a name.

   

   • The licence, you just leave it blank, the default will be an ISC license.

   

   • After that, it will show the data in the package.json file that shows the information of the project that you have filled in the command line.
   • Press Enter to create a JavaScript project.

   

   • After that, you will see the package.json file that has been created after you create a JavaScript project.

   

   Let's write a simple hello world API using ExpressJS

   1. Install the ExpressJS framework to your project, by enter the command line npm install express

   • After you installed the express framework to your projec, you will see the package.json has been updated, its add the dependencies object to the file.

   • dependencies is the object that contains version of the module of your framework, library that you use in your project. 👇🏻

    

   {
     "name": "simple_express",
     "version": "1.0.0",
     "description": "Simple ExpressJS project",
     "main": "index.js",
     "scripts": {
       "test": "echo \"Error: no test specified\" && exit 1"
     },
     "author": "",
     "license": "ISC",
     "dependencies": {
       "express": "^4.18.2"
     }
   }

   3. Write the following code

   

4. Check it's Work Go to Browser search localhost:3000
   

     5. Try to add more route by implement with data.json

• • Check Result localhost:3000/banks 

    What you see ?

  • You will see that if that path is the same, the backend application will send the data correctly.