inherits
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.
const util = require('node:util');
const EventEmitter = require('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: "${data}"`);
});
stream.write('It works!'); // Received data: "It works!"
Content copied to clipboard
ES6 example using class
and extends
:
const EventEmitter = require('node:events');
class MyStream extends EventEmitter {
write(data) {
this.emit('data', data);
}
}
const stream = new MyStream();
stream.on('data', (data) => {
console.log(`Received data: "${data}"`);
});
stream.write('With ES6');
Content copied to clipboard
Since
v0.3.0