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Classes and Inheritance
Question 1
What is the purpose of the constructor method in a class?
- A
To define static properties of a class
- B
To initialize object properties
- C
To inherit methods from another class
- D
To execute a class directly
Question 2
How do you define a static method in a class?
- A
Using the static keyword
- B
By defining the method inside the constructor
- C
Using the classMethod keyword
- D
By adding the method directly to the prototype
Question 3
Which keyword is used for inheritance in JavaScript classes?
- A
inherit
- B
extends
- C
prototype
- D
super
Question 4
What does the super keyword do?
- A
Calls the parent class's constructor
- B
Creates a new object in the class
- C
Defines a static method
- D
Overrides the parent class methods
Question 5
How do you define a private field in a class?
- A
By using private keyword
- B
By using _ before the field name
- C
By using # before the field name
- D
By declaring it inside the constructor
Question 6
Which of the following is an example of a Mixin?
- A
A function that adds methods to a class
- B
A class that extends another class
- C
A method inside a static class
- D
A constructor with parameters
Question 7
What will the following code log?
class Parent {
greet() {
return "Hello";
}
}
class Child extends Parent { }
const c = new Child();
console.log(c.greet());
- A
Error
- B
Hello
- C
Undefined
- D
Greet is not a function
Question 8
What is a key difference between a method and a static method?
- A
Methods are bound to the instance, while static methods are bound to the class
- B
Static methods are always private
- C
Methods can only be defined inside the constructor
- D
Static methods can only access private fields
Question 9
Which statement about inheritance is correct?
- A
A class can extend multiple classes.
- B
A class can extend only one class.
- C
Inheritance is not possible in JavaScript.
- D
A class must use super to inherit properties but not methods.
Question 10
Which of the following statements about private fields is true?
- A
They are accessible by subclasses.
- B
They can only be declared using the # syntax.
- C
They can be accessed directly from outside the class.
- D
They can only be used in static methods.
There are 10 questions to complete.
