How do you define a constructor function for crea...

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 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 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 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 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 define a method 'sayHello' in an obj...

A). person.sayHello = function() {};

B). person.sayHello: function() {};

C). person.sayHello = () {};

D). person.sayHello = function {};

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);

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 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.