Javascript object inheritance

Question

Please help me in understanding this piece of code. ``` var person = { 'first-name': 'FirstName', 'last-name': 'LastName', 'gender': 'Male' }; var anotherPerson = new Object(person); anotherPerson.desig = 'Designation'; console.log('Another person designation: ' + anotherPerson['desig'] + ', person designation: ' + person['desig']); ``` I expected the output to be `Another person designation: Designation, person designation: undefined` but to my surprise I found it to be ``Another person designation: Designation, person designation: Designation`. According to me `anotherPerson` is extending `person` object and properties set to `anotherPerson` should not be visible to `person` object. Am I wrong here? Or is that both the object are pointing to the same location? [EDIT] Now there are even more surprises. I added the following code to the above. ``` person.place = 'XYZ'; console.log(person['place'] + ', ' + anotherPerson['place']); // Expected: XYZ, undefined. Result: XYZ, XYZ. ``` Base…

Accepted Answer

You are not doing extending or any kind of inheritance.

This comes closer:

```
var Person = function () {
    this["first-name"] = 'FirstName',
    this["last-name"] = 'LastName',
    this["gender"] = 'Male'
};

var person = new Person();
var anotherPerson = new Person();
```

Now you have two seperate instances of `Person`. If you also want `anotherPerson` to be a subclass ..

```
var Person = function () {
    this["first-name"] = 'FirstName',
    this["last-name"] = 'LastName',
    this["gender"] = 'Male'
};

var AnotherPerson = function () {
    this.desig = "Designation";
}
AnotherPerson.prototype = new Person();   // inherit from Person
AnotherPerson.prototype.constructor = AnotherPerson;  // reset constructor

var person = new Person();
var anotherPerson = new AnotherPerson();

console.log(person.desig); // undefined
console.log(anotherPerson.desig); // Designation
```

Javascript object inheritance

Solution

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