How to Access Global Variables in Node.js Modules?

Understanding Global Variables in Node.js

In Node.js, global variables can be defined by assigning values to the global scope without declaring the variable keyword. However, it's important to note that accessing global variables from required modules may require an alternative approach.

Accessing Global Variables from Required Modules

To make a variable defined in a module available in other modules, the conventional approach with require() does not suffice. Instead, you can utilize the global variable key to manually add properties to the global scope.

Example:

To access the underscore library within all required modules, you can define the following:

<code class="javascript">global._ = require('underscore');</code>

This makes the _ object available throughout the application.

Alternative Approach: Express.js app.set

Express.js provides the app.set function to store and retrieve data within the application context. This approach is useful when working with Express-specific variables.

Example:

<code class="javascript">app.set('myVariable', 'value');
const myVariable = app.get('myVariable');</code>

This assigns the value "value" to the myVariable property, which can then be accessed via the app.get() method.

Recommendation:

While using global variables can be convenient, it's generally recommended to limit their usage due to potential naming collisions and decreased code readability. Consider using alternative approaches such as dependency injection or passing values as parameters instead.

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