Q
Which of the following will cause an error when used with a constant object in JavaScript?

Answer & Solution

Answer: Option D
Solution:
Reassigning the object reference to a new object will cause an error when using a constant object in JavaScript.
Related Questions on Average

Which statement about constant objects in JavaScript is correct?

A). A. Constant objects can have their properties reassigned

B). B. Constant objects cannot have properties added or removed

C). C. Constant objects are only applicable to primitive values

D). D. Constant objects are mutable

What is the correct way to modify a property of a constant object in JavaScript?

A). A. Use the delete keyword

B). B. Use the const keyword for the property

C). C. Use dot notation or bracket notation to access and modify the property

D). D. Use Object.freeze() to freeze the object

What happens if you use Object.freeze() on a constant object in JavaScript?

A). A. The object reference becomes mutable

B). B. The properties of the object become immutable

C). C. The object becomes frozen and cannot be modified

D). D. A TypeError is thrown

Which of the following is a valid way to define a constant object in JavaScript?

A). A. const obj = { a: 1, b: 2 };

B). B. const obj = new Object({ a: 1, b: 2 });

C). C. Both A and B

D). D. None of the above

How can you ensure that a constant object remains unchanged in JavaScript?

A). A. Use Object.preventExtensions()

B). B. Use Object.freeze() to freeze the object

C). C. Use const for each property

D). D. All of the above

What is the output of the following code snippet?

A). A. { x: 10, y: 20 }

B). B. { x: 20, y: 10 }

C). C. { x: 10 }

D). D. Error

What happens if you try to modify a property of a frozen object in JavaScript using Object.freeze()?

A). A. The property is modified successfully

B). B. A TypeError is thrown

C). C. The property is deleted

D). D. The object becomes mutable

What is the output of the following code snippet?

A). A. { a: 1, b: 2, c: 3 }

B). B. { a: 1, b: 2 }

C). C. { c: 3 }

D). D. Error

How can you check if an object is frozen in JavaScript?

A). A. Using the frozen property

B). B. Using the isFrozen() method

C). C. Using the Object.isFrozen() method

D). D. All of the above

What is the result of the expression Object.keys(person).length for the following code snippet?

A). A. 1

B). B. 2

C). C. 3

D). D. Error