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 will console.log(obj.toString()) output?
A). The string representation of...
B). The object itself.
C). An error.
D). 1
How do you define a constructor function for crea...
A). function Car(make, model) { thi...
B). Car(make, model) { this.make = m...
C). var Car = function(make, model) ...
D). Car = function(make, model) { t...
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 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 access nested properties in an object?
A). obj.property.nestedProp (B21)
B). obj['property']['nestedProp'] (C21)
C). obj.property['nestedProp'] (D21)
D). obj['property'].nestedProp (E21)
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.
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.
How do you access a property called 'name' from an...
A). person.name
B). person['name']
C). person->name
D). person::name
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);