Nodejs: What is the Default wrapper function ??

In Node.js, the CommonJS module system automatically wraps every module in a function. This default wrapper function encapsulates the module’s code and provides a private scope for its variables and functions.

Here’s an example of what the default wrapper function looks like:

(function (exports, require, module, __filename, __dirname) {
  // Your module code actually goes here
});

When you define a module in Node.js, the module’s code is executed within this wrapper function, with the following parameters:

• exports: An object that is used to define what should be exported from the module.
• require: A function that is used to import other modules into the current module.
• module: An object that represents the current module and its properties, such as its filename, exports, and so on.
• __filename: The absolute path of the current module file.
• __dirname: The absolute path of the directory that contains the current module file.

This default wrapper function is what makes it possible to define private variables and functions within a module that are not accessible from other modules, unless explicitly exported.