What is Node js module exports and how to use it?

module.exports is a special object in Node.js that is used to expose objects, functions, or variables to the module system. It allows you to reuse code in your application by breaking it down into smaller, modular units called “modules”.

To use module.exports, you can assign the object, function, or variable that you want to expose to it. For example:

module.exports = {
  foo: 'bar',
  add: (a, b) => a + b
};

In this example, the module.exports object is being used to expose an object with two properties: foo and add. The foo property is a string, and the add property is a function that adds two numbers.

To use a module in another file, you can use the require function and assign the result to a variable. For example:

const myModule = require('./myModule');

console.log(myModule.foo); // 'bar'
console.log(myModule.add(1, 2)); // 3

In this example, the myModule variable is assigned the value of the module.exports object from the myModule file. You can then access the properties of the object using dot notation.

Keep in mind that module.exports can only be assigned a single value, so if you want to expose multiple objects, functions, or variables, you can either wrap them in an object or use multiple module.exports statements.