How to Access an Immediately Invoked Function Expression Variable in Node.js Using require

Learn how to effectively access an `Immediately Invoked Function Expression (IIFE)` variable across different files in Node.js. This guide explains the steps needed to use the `require` function to make your modules accessible. --- This video is based on the question https://stackoverflow.com/q/63784320/ asked by the user 'OmegaSheep' ( https://stackoverflow.com/u/7376773/ ) and on the answer https://stackoverflow.com/a/63784546/ provided by the user 'jfriend00' ( https://stackoverflow.com/u/816620/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Accessing an Immediately Invoked Function Expression variable in Node.js in another file using require Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l... The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Accessing an Immediately Invoked Function Expression Variable Across Files in Node.js In the world of JavaScript, especially when dealing with Node.js, modular programming is key to maintaining clean and manageable code. However, sometimes you might encounter issues when trying to access variables defined inside an Immediately Invoked Function Expression (IIFE) from another file. This post tackles a common question regarding how to access the doThing() method from an IIFE in a Node.js project using the require function. Understanding the Problem Suppose you have two JavaScript files: Monitor.js and Test.js. Inside Monitor.js, you defined an IIFE which contains a method called doThing(). Here’s a quick look at what that file might look like: [[See Video to Reveal this Text or Code Snippet]] Now, you want to access the doThing() method in Test.js, but running the following line does not seem to work: [[See Video to Reveal this Text or Code Snippet]] While including Monitor.js directly in the frontend works perfectly fine, accessing it through Node.js proves to be tricky without the right steps. The Solution: Exporting the IIFE To solve this issue, you need to ensure that your IIFE (MONITOR) is exported properly. By default, variables defined in one file are not accessible in other files unless explicitly exported. Here’s how to do it: Step 1: Export the MONITOR Object At the bottom of your Monitor.js, add the following line to export the MONITOR variable: [[See Video to Reveal this Text or Code Snippet]] This line makes the MONITOR object available for other files to access through require. Your Updated Monitor.js After making the modification, Monitor.js should look like this: [[See Video to Reveal this Text or Code Snippet]] Step 2: Accessing the Exported Function in Test.js Now that you've exported MONITOR, you can easily call doThing() in your Test.js file. Simply do the following: [[See Video to Reveal this Text or Code Snippet]] Important Points to Remember Use module.exports: This is crucial for making your variables and functions accessible across different files in Node.js. Return Values: If you want your methods to return values, ensure you include a return statement in the function definition. Conclusion By following these simple steps, you can efficiently share and access your IIFE-created functions across different files in your Node.js applications. Remember to always export the variables or objects you want to use elsewhere. Happy coding!