23 lines
679 B
Markdown
23 lines
679 B
Markdown
|
---
|
||
|
|
tags:
|
||
|
|
- Programming_Languages
|
||
|
|
- backend
|
||
|
|
- node-js
|
||
|
|
- node-modules
|
||
|
|
---
|
||
|
|
|
||
|
|
## The Module Wrapper Function
|
||
|
|
|
||
|
|
When Node runs each of our module files are wrapped within an immediately-invoked function expression that has the following parameters:
|
||
|
|
|
||
|
|
````js
|
||
|
|
(function (exports, require, module, __filename, __dirname))
|
||
|
|
|
||
|
|
````
|
||
|
|
|
||
|
|
This is called the **module wrapper function**
|
||
|
|
|
||
|
|
Note that one of these parameters is the [module object](Modules.md#structure-of-a-module).
|
||
|
|
|
||
|
|
Within any module we can access these parameters: you can think of them as metadata about the module itself. `__filename` and `__dirname` are particularly useful when writing to files and modifying directories.
|