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 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
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 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
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
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 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 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 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