Difference between JavaScript Linkage Object() and reference with =

Question

I was going through the videos from Crockford and found out Object() linkage topic.

I did not get the exact difference between Object() linkage and assignment though.

Can someone put some light to clear this up.

Below is the snippet code and result when executed in Chrome Browser

var myObj= {name:"Jack", age:25};

var myLinkObj= Object(myObj);

var myRef=myObj;


myLinkObj.name="John";
myRef.add="India";


alert(myObj.name);  // output John
alert(myObj.add); //output "India"

So what is the extra feature that I get form Object(). I find it is similar to value reference.

There is absolutely zero point in using Object() here, myObj === myLinkObj. What part of which video do you refer to? — Bergi
– Bergi, Commented Aug 26, 2014 at 11:40
I found in Douglas Crockford: "The JavaScript Programming Language"/2 of 4 video during Linkage explanation. Eventhough example I used is different from what he has shown. — Brinal
– Brinal, Commented Aug 26, 2014 at 11:51
yui.zenfs.com/theater/crockford-tjpl-2.m4v Linkage topic starts at around 16:00 min — Brinal
– Brinal, Commented Aug 27, 2014 at 3:11

Bergi · Accepted Answer · 2014-08-27 12:10:55Z

2

So what is the extra feature that I get form Object(). I find it is similar to value reference.

That's true. The Object function does simply return the reference to the given object.

However, that's not what Crockford is talking about in his video. He is trying to explain prototype inheritance, and he does not use the Object function for that but his object function that he only presents on his website and does not mention this in the talk (maybe another, earlier video?). It is defined as following:

function object(o) {
    function F() {}
    F.prototype = o;
    return new F();
}

However, that website is a bit outdated, and the language has evolved. Since EcmaScript 5 we have a native function with this functionality in the language: Object.create. You'd just do

var object = Object.create;

answered Aug 27, 2014 at 12:10

Bergi

671k162 gold badges1k silver badges1.5k bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Brinal · Accepted Answer · 2014-08-27 06:23:38Z

0

var myObj= {name:"Jack", age:25};

var myLinkObj= Object.create(myObj);

myLinkObj.name="John";
myLinkObj.add="India";


alert(myLinkObj.name); //John
alert(myLinkObj.age); //25
alert(myLinkObj.add);//India
alert(myObj.name);//Jack

This works as prototype inheritance concept. myLinkobj inherit the the properties from myObj in this case. Thanks, Brinal

answered Aug 27, 2014 at 6:23

Brinal

3023 silver badges19 bronze badges

Collectives™ on Stack Overflow

Difference between JavaScript Linkage Object() and reference with =

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related