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

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

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 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

Which statement is true about constant objects in JavaScript?

A). A. The properties of a constant object cannot be changed

B). B. Constant objects are frozen and immutable

C). C. Constant objects cannot have properties added or deleted

D). D. The object reference can be reassigned

Which statement best describes the behavior of a constant object in JavaScript?

A). A. The object and its properties cannot be changed

B). B. The object reference cannot be reassigned

C). C. All properties are immutable

D). D. The object cannot be modified after declaration

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 data type of a constant object in JavaScript?

A). A. Object

B). B. Array

C). C. Function

D). D. String

How can you prevent modifications to the properties of a JavaScript object?

A). A. Use Object.preventExtensions()

B). B. Use const for each property

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

D). D. All of the above

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 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