Why use util.inherits and .call for inheritance in Node.js

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I am wondering why, when creating a new stream class in node, I need to use both call and util.inherits

For instance, in the following code, which is used to create a readable stream, I have to use both:

var Readable = require('stream').Readable;
var util = require('util');


var MyStream = function (options) {
    Readable.call(this, options)
}

util.inherits(MyStream, Readable); //Hasn't this already inherited all methods from Readable via "call"

var stream = new MyStream();

It seems to be that Readable.call is calling the constructor from Readable and therefore the util.inherits is unnecessary.

asked 2 mins ago

Startec

591

1 Answer

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0

util.inherits will merge the prototype chain from Readable into MyStream. Both are required for a more complete sense of inheritance.

answered 4 secs ago

Mike

1,042

Why use util.inherits and .call for inheritance in Node.js