What will console.log(obj.toString()) output?

What does the Object.values(obj) method return?

A). An array of object keys.

B). An array of object values.

C). An array of object properties.

D). An array of object methods.

What happens if you access a non-existent property...

A). It returns undefined.

B). It throws an error.

C). It returns null.

D). It returns true.

What is the purpose of the 'super' keyword in a ...

A). It calls methods from the paren...

B). It creates a new instance of the...

C). It refers to the current object.

D). It checks for property existence.

How do you inherit properties and methods from a...

A). class SubClass extends SuperClas...

B). class SubClass inherits SuperCla...

C). class SubClass implements Super...

D). class SubClass derives SuperCla...

How can you remove a property 'email' from an obj...

A). delete user.email;

B). user.remove('email');

C). user.email = null;

D). user.pop('email');

How do you check if an object has a property 'col...

A). 'color' in obj

B). obj.hasProperty('color');

C). obj.contains('color');

D). obj.propertyExists('color');

How do you add a new property 'age' with value 25...

A). person.age = 25;

B). person['age'] = 25;

C). person.add('age', 25);

D). person.push('age', 25);

How do you iterate over all properties of an obj...

A). for (var prop in person)

B). forEach(prop in person)

C). for (var prop of person)

D). forEach(prop of person)

How do you get the number of properties in an obj...

A). Object.keys(book).length

B). book.countProperties()

C). book.totalProperties()

D). book.length()

What does Object.keys(obj) return?

A). An array of object keys.

B). An array of object values.

C). An array of object properties.

D). An array of object methods.