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:

console.log(global);
console.log(process.pid);
console.log(__dirname);

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.

The above is the detailed content of What are the global variables in nodejs. For more information, please follow other related articles on the PHP Chinese website!