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
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
How can you change the properties of a constant object in JavaScript?
A). A. Use Object.freeze()
B). B. Use const for each property
C). C. Use the delete keyword to remove properties
D). D. Use dot notation or bracket notation
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 is the data type of a constant object in JavaScript?
A). A. Object
B). B. Array
C). C. Function
D). D. String
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 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
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
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 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