What are the global variables in nodejs

The following global variables exist in Node.js: Global object: global Core module: process, console, require Runtime environment variables: __dirname, __filename, __line, __column Constants: undefined, null, NaN, Infinity, - Infinity

Global variables in Node.js

There are several built-in global variables in Node.js:

1. Global object

• global: Represents the global object of the currently executing script. All other global variables are properties of this object.

2. Core module

• #process: Provides detailed information and control of the Node.js process.
• console: Provides console output and debugging functions.
• require: used to load and access other modules.

3. Runtime environment variable

• #__dirname: Contains the absolute path to the directory where the current module is located.
• __filename: Contains the absolute path of the current module file.
• __line: The line number of the line of code currently being executed.
• __column: The column number of the line of code currently being executed.

4. Constant

• undefined: Undefined value.
• null: Indicates a null value.
• NaN: non-numeric value.
• Infinity: Positive infinity.
• -Infinity: Negative infinity.

Using global variables

Global variables can be accessed directly from any Node.js script. For example:

<code class="javascript">console.log(global);
console.log(process.pid);
console.log(__dirname);</code>

Note:

• Global variables are visible throughout the application and should be used with caution.
• Avoid modifying global variables provided by core modules, as this may cause unexpected behavior.

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