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

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.

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.

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)

What is the purpose of the 'this' keyword in a co...

A). It refers to the new object bei...

B). It refers to the global object.

C). It refers to the current object.

D). It refers to the parent object.

What is the output of console.log(obj.prop) if ob...

A). It prints undefined.

B). It throws an error.

C). It prints null.

D). It prints true.

How do you access a property called 'name' from an...

A). person.name

B). person['name']

C). person->name

D). person::name

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');

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.