How to check if Node.js was installed successfully

Node.js is a JavaScript running environment based on the Chrome V8 engine. It enables JavaScript to run on the server side and enables very efficient server-side programming. Installing Node.js is already very easy for developers, but sometimes we need to check whether the installation was successful. This article will describe how to check whether Node.js was installed successfully.

1. Check the Node.js version number

After installing Node.js, the first thing to check is the Node.js version number. Enter the following command at the command line:

node -v

If you see a series of numbers, it means you have successfully installed Node.js. It will display your currently installed Node.js version number.

2. Checking Node.js through REPL

Node.js comes with an interactive interpreter environment REPL (Read-Eval-Print Loop) that allows you to type directly JavaScript code and execute it. Enter the following command at the command line:

node

This will start a Node.js interpreter. You can then enter the following code:

console.log('Node.js installed successfully!');

Press Enter and you will see the output "Node.js installed successfully!". This means you have successfully installed Node.js.

3. Install npm from the command line

npm is the package manager for Node.js. It is a command line tool for installing and managing Node.js modules. . If you have installed Node.js on your computer before, npm is already installed. If you want to check whether npm is installed, you can enter the following command at the command line:

npm -v

If you see a string of numbers, npm has been installed successfully.

4. Install Express from the command line

Express is one of the most popular web application frameworks for Node.js. If you have successfully installed Node.js, you can use npm to install Express. Enter the following command at the command line:

npm install -g express

If you see the output "npm ERR!", something might have gone wrong. Please make sure your computer has internet access and check that you are using the correct npm command.

Summary

Installing Node.js on your computer is not a complicated task, but it is still important to check whether the installation was successful. Checking the version number, using a REPL environment, and installing npm and Express are all good ways to check whether Node.js was installed successfully. If you encounter any problems, please check the documentation for Node.js or refer to related resources.

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