function inherits
Usage in Deno
import { inherits } from "node:util";
inherits(constructor: unknown,superConstructor: unknown,): void
Usage of util.inherits()
is discouraged. Please use the ES6 class
and extends
keywords to get language level inheritance support. Also note
that the two styles are semantically incompatible.
Inherit the prototype methods from one constructor into another. The
prototype of constructor
will be set to a new object created from superConstructor
.
This mainly adds some input validation on top ofObject.setPrototypeOf(constructor.prototype, superConstructor.prototype)
.
As an additional convenience, superConstructor
will be accessible
through the constructor.super_
property.
import util from 'node:util';
import EventEmitter from 'node:events';
function MyStream() {
EventEmitter.call(this);
}
util.inherits(MyStream, EventEmitter);
MyStream.prototype.write = function(data) {
this.emit('data', data);
};
const stream = new MyStream();
console.log(stream instanceof EventEmitter); // true
console.log(MyStream.super_ === EventEmitter); // true
stream.on('data', (data) => {
console.log(`Received data: "${data}"`);
});
stream.write('It works!'); // Received data: "It works!"
ES6 example using class
and extends
:
import EventEmitter from 'node:events';
class MyStream extends EventEmitter {
write(data) {
this.emit('data', data);
}
}
const stream = new MyStream();
stream.on('data', (data) => {
console.log(`Received data: "${data}"`);
});
stream.write('With ES6');
void