Question

166

What is returned from a constructor?

rated 0 times [ 171] [ 5] / answers: 1 / hits: 44066 / 14 Years ago, wed, july 28, 2010, 12:00:00

If I return some value or object in constructor function, what will the var get?

function MyConstroctor()

{

    //what in case when return 5;

    //what in case when return someObject;

}



var n = new MyConstroctor();

what n will get in both cases?

Actually its a quiz question, what will be the answer?

What is returned from a custom object constructor?

a)The newly-instantiated object

b)undefined - constructors do not return values

c)Whatever is the return statement

d)Whatever is the return statement; the newly-instantiated object if no return statement

Answers

Only authorized users can answer the question. Please sign in first, or register a free account.

tobyl

Add To Favorites

Follow

Total Points: 598

Total Questions: 110

Total Answers: 114

Location: Vietnam

Member since Sat, Feb 12, 2022

2 Years ago

tobyl questions

1 How to update State of chart.js in React

Tue, Aug 10, 21, 00:00, 3 Years ago

1 Angular Jasmine this service method is a not a function

Wed, Jan 13, 21, 00:00, 3 Years ago

1 Double sided input slider in React

Tue, Dec 1, 20, 00:00, 4 Years ago

1 Formatting Strings to Datetime using specific formats in Luxon

Mon, Nov 2, 20, 00:00, 4 Years ago

1 Cannot find module 'react-native-reanimated/plugin' from /projectFolder

Thu, Sep 3, 20, 00:00, 4 Years ago

View All

answered 14 Years ago katharinek · Accepted Answer

I found this great link:

JavaScript: Constructor Return Value

The second piece of magic eluded to above is the ability for a
constructor to return a specific, possibly pre-existing object, rather
than a reference to a new instance. This would allow you to manage the
number of actual instances yourself if needed; possibly for reasons of
limited resources or whatnot.

var g_deebee = new Deebee();

function Deebee() { return g_deebee; }

var db1 = new Deebee();

var db2 = new Deebee();

if (db1 != db2)

  throw Error(JS constructor returned wrong object!);

else console.log('Equal');