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 get the number of properties in an obj...
A). Object.keys(book).length
B). book.countProperties()
C). book.totalProperties()
D). book.length()
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...
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 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 method 'sayHello' in an obj...
A). person.sayHello = function() {};
B). person.sayHello: function() {};
C). person.sayHello = () {};
D). person.sayHello = function {};
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');
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 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 do you add a method to an object created wit...
A). this.methodName = function() {}
B). this.methodName: function() {};
C). this.methodName = () {}
D). this.methodName: () {}