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Nodejs Process & Global Objects

Nodejs Process & Global Objects

Node.js is an open-source, cross-platform, back-end JavaScript runtime environment that runs on the V8 engine and executes JavaScript code outside a web browser. In this article, we will explore the concept of Nodejs Process and Global Objects.

Node.js Global Objects​

Global objects in Node.js are available in all modules. You don't need to include these objects in your application; they can be used directly. Some of the most commonly used Node.js global objects are:

  • __dirname: This is a string that represents the directory name of the current module.
  • __filename: This is a string that represents the file name of the current module.
  • console: This is used to print to stdout and stderr.
  • process: This is used to get information on the current process of Node.js.
  • Buffer: This is used to handle binary data.
  • setImmediate(callback[, ...args]): This is used to execute a callback function immediately after the completion of the current event loop.
  • clearImmediate(immediateObject): This stops an immediateObject, as created by setImmediate(), from triggering.

Node.js Process Object​

Just like the console and Buffer, process is also a global object that provides information about, and control over, the current Node.js process. It can be accessed from anywhere and it is primarily used to get environment information.

The process object is an instance of EventEmitter and emits the following events:

  • 'exit': This event is emitted when the Node.js process is about to exit.
  • 'uncaughtException': This event is emitted when an exception bubbles all the way back to the event loop.
  • 'warning': This event is emitted whenever Node.js emits a warning.

The process object has various methods and properties. Here are some of them:

  • process.argv: This is an array containing the command-line arguments passed when the Node.js process was launched.
  • process.env: This is an object that holds the user environment.
  • process.exit([code]): This method instructs Node.js to terminate the process.
  • process.pid: This is the PID of the process.
  • process.version: This is a property that returns a string representing the Node.js version.

Conclusion​

Understanding the role of Node.js' global and process objects is crucial to effectively using the Node.js runtime. These objects provide vital information about the environment in which your application is running, and allow you to control and interact with the current Node.js process.

Remember, experimenting and practicing with these objects will help you understand their functionality better. So, make sure to try out different methods and properties of these objects and see the results for yourself. Happy coding!