Quick example to demonstrate that a file required into different files in a Node.js application is in fact the same closure.

In reality this means that if anything is stored or cached in the the required file, any file that requires it can access the cached info.

This is very useful when building applications, but can take you by surprise if you're not aware that this is how it works!

Simply run node app.js in the comman line.

Note: Use Node.js v 6+ to avoid ES6 warnings

app.js requires a files called util.js.

util.js has a local variable myData initialised to null. It exposes two functions:

1. set - takes a single parameter and assigns the value to the myData variable.
2. get - returns the myData variable

app.js calls the set method of util sending it a string value.

app.js calls the get method of util and outputs it as a console log.

app.js requires another file file2.js.

file2.js requires in the util.js file.

file2.js calls the get method of util and outputs it as a console log.

Both console.log statements have the same value, as the data is cached inside the util.js file.