22 lines
679 B
Markdown
22 lines
679 B
Markdown
---
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tags:
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- Programming_Languages
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- backend
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- node-js
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- node-modules
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---
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## The Module Wrapper Function
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When Node runs each of our module files are wrapped within an immediately-invoked function expression that has the following parameters:
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````js
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(function (exports, require, module, __filename, __dirname))
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````
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This is called the **module wrapper function**
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Note that one of these parameters is the [module object](Modules.md#structure-of-a-module).
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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.
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