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
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.
How do you add a method to an object created wit...
A). this.methodName = function() {}
B). this.methodName: function() {};
C). this.methodName = () {}
D). this.methodName: () {}
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 access a property called 'name' from an...
A). person.name
B). person['name']
C). person->name
D). person::name
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 do you create an instance of the 'Car' objec...
A). var myCar = new Car('Toyota', ...
B). var myCar = Car('Toyota', 'Corol...
C). var myCar = create Car('Toyota',...
D). var myCar = construct Car('Toyo...
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.
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');