What is util.inherits() in Node.js?
util.inherits is a function of Node.js that is in the util module.
In util.inherit, the constructor inherits the prototype methods from one to another. The prototype of that constructor is placed in a new object created with superConstructor.
The
utilmodule gives utility functions that can be used for debugging purposes.
To access the util.inherit function, the util module needs to be accessed, as shown below.
const util = require('util');
Syntax
util.inherits(constructor, superConstructor)
Parameters
The function takes in two parameters.
-
constructor: The function that the programmer wants to be inherited from the class. -
superConstructor: A function that is primarily used for adding/inheriting input validation.
Return value
An undefined value is returned upon successful execution of the function.
Example
The code below shows how the util.inherits function operates.
Mystream and emitEvent are both passed as arguments to util.inherits. MyStream is a constructor, whereas emitEvent is a superConstructor.
const util = require('util');const emitEvent = require('events');// MyStream function calls EventEmitterfunction MyStream() {emitEvent.call(this);}console.log("util.inherit returns :",util.inherits(MyStream, emitEvent));
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