JavaScript Objects

This section covers the questions for JavaScript Objects to clear all your concepts.

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Question 1

Which is the correct way to create an object in JavaScript?

  • let obj = Object();

  • let obj = { key: "value" };

  • let obj = new Object("key", "value");

  • let obj = Object.create();

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Question 2

How do you access the property of an object using bracket notation?

  • obj.key

  • obj["key"]

  • obj(key)

  • obj->key

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Question 3

Which of the following is a valid way to define a function as a property of an object?

  • obj.func = function() { ... }

  • obj.func = () => { ... }

  • Both

  • None of the above

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Question 4

Which method is used to merge two objects?

  • Object.assign()

  • Object.merge()

  • Object.create()

  • Object.combine()

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Question 5

What is the purpose of the prototype property in JavaScript objects?

  • To create new properties in an object

  • To define methods and properties for inheritance

  • To store the type of the object

  • To delete existing properties

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Question 6

Which of the following creates a deep copy of an object?

  • JSON.stringify() and JSON.parse()

  • Object.assign()

  • Object.create()

  • Object.freeze()

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Question 7

What will the following code log?

JavaScript 
const obj = { a: 1 };
obj.b = 2;
console.log(obj);


  • { a: 1 }

  • { a: 1, b: 2 }

  • Error

  • undefined

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Question 8

Which of the following is a valid getter in an object?

  • get name() { return this._name; }

  • getter name() { return this._name; }

  • get: function() { return this.name; }

  • name.get { return this._name; }

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Question 9

What will the following code log?

JavaScript 
const obj = { a: 1, b: 2 };
delete obj.a;
console.log(obj)


  • { b: 2 }

  • { a: null, b: 2 }

  • { a: undefined, b: 2 }

  • Error

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Question 10

What is the purpose of Object.freeze()?

  • To prevent new properties from being added

  • To make the object immutable

  • To prevent existing properties from being changed

  • All of the above

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There are 10 questions to complete.

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