Q
What does the const keyword do when used to declare an object in JavaScript?

Answer & Solution

Answer: Option B
Solution:
The const keyword in JavaScript prevents reassignment of the object reference but does not make the object itself immutable or freeze its properties.
Related Questions on Average

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

What happens if you try to reassign a constant object to a new object in JavaScript?

A). A. No error, the assignment is successful

B). B. TypeError is thrown

C). C. SyntaxError is thrown

D). D. ReferenceError is thrown

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 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 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

Which of the following will result in an error when using a constant object in JavaScript?

A). A. Modifying an existing property

B). B. Adding a new property

C). C. Reassigning the object reference

D). D. None, all operations are valid with constant objects

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

What happens if you try to delete a property from a constant object in JavaScript?

A). A. The property is deleted successfully

B). B. A TypeError is thrown

C). C. A SyntaxError is thrown

D). D. Nothing happens

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