Creating and Using Employee Object in JavaScript

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson
Download our mobile app to listen on the go
Get App

Questions and Answers

In JavaScript, when does it make sense to use object composition?

  • When the superclass and subclass share the same properties
  • When the subclass has no access to features of the superclass
  • When the subclass adds new features to the superclass
  • When one object has a type of another object (correct)

What would be the result of calling arr.unshift('Grace') after initializing the NumberArray object?

  • It would remove the last element from the array
  • It would add 'Grace' to the end of the array
  • It would throw a TypeError because the method isn't defined (correct)
  • It would display 'Grace' as the first element of the array

What does data hiding refer to in terms of object composition?

  • Sharing all data publicly between objects
  • Exposing all data for external manipulation
  • Allowing unrestricted access to private data
  • Keeping data inaccessible from outside the object (correct)

Which term is synonymous with object composition?

<p>Encapsulation (A)</p> Signup and view all the answers

What does it mean when one object has a type of another object in terms of object composition?

<p>One object can be treated as an instance of another object (A)</p> Signup and view all the answers

Why would a subclass restrict access to features of the superclass in object composition?

<p>To prevent misuse or unintended modifications by the subclass (A)</p> Signup and view all the answers

What is the main benefit of using inheritance in object-oriented programming?

<p>Reduce complexity and redundancy by promoting code reuse (A)</p> Signup and view all the answers

Which syntax is used for a concise method declaration in JavaScript?

<p>Shorthand method syntax (A)</p> Signup and view all the answers

In the context of classes in JavaScript, what does the 'super' keyword refer to?

<p>A method to access the parent class' constructor (B)</p> Signup and view all the answers

What action does the lib_trips.js file take if the miles and gallons values in the Trip class are not valid?

<p>Returns false (C)</p> Signup and view all the answers

What benefit does using JavaScript libraries provide?

<p>Eases code understanding and reusability (C)</p> Signup and view all the answers

Which operator is used to delete a property from an object in JavaScript?

<p>delete operator (C)</p> Signup and view all the answers

In the provided code snippet, what does 'emp instanceof Person' evaluate to?

<p>True (B)</p> Signup and view all the answers

What happens if a non-number value is pushed into a 'NumberArray' object?

<p>A runtime error is thrown (D)</p> Signup and view all the answers

What does the 'instanceof' operator do in JavaScript?

<p>Checks if an object is an instance of a specific class (D)</p> Signup and view all the answers

Which term refers to a class that inherits properties and methods from another class?

<p>Subclass (B)</p> Signup and view all the answers

In the context of JavaScript, what is meant by 'reference to an object'?

<p>Pointing to the memory location of an object (C)</p> Signup and view all the answers

Which aspect of code organization is encouraged by JavaScript libraries?

<p>Separation of concerns (C)</p> Signup and view all the answers

What is the purpose of the constructor in the Invoice class?

<p>To store and initialize the subtotal and tax rate (D)</p> Signup and view all the answers

What type of property in JavaScript can only be read but not written to?

<p>Read-only property (D)</p> Signup and view all the answers

How many arguments are passed to the constructor when creating invoice2?

<p>Two (A)</p> Signup and view all the answers

Which jQuery method is used to empty the HTML content of an element with the id 'tasks'?

<p>$('#tasks').empty() (D)</p> Signup and view all the answers

What does the class Trip represent in the Trips app?

<p>A data structure for storing trip information (A)</p> Signup and view all the answers

Which method is responsible for clearing the task list in the Trip class?

<p>taskList.clear() (D)</p> Signup and view all the answers

In the context of the Invoice class, what does the statement const invoice = new Invoice(100, 0.0875); achieve?

<p>Creates a new invoice object with a subtotal of 100 and a tax rate of 0.0875 (B)</p> Signup and view all the answers

What does the 'isValid' property in the Trip class indicate?

<p>The miles and gallons values are valid (C)</p> Signup and view all the answers

What is the primary role of the fullName method in the Person class?

<p>To return the combined first name and last name as a single string (D)</p> Signup and view all the answers

When creating a new Person object, what parameters are required in the constructor?

<p>First name and last name (A)</p> Signup and view all the answers

What does the statement console.log(p instanceof Object); verify about object p?

<p><code>p</code> is an instance of an Object class (A)</p> Signup and view all the answers

Flashcards are hidden until you start studying

More Like This

OwnProperty in JavaScript
10 questions

OwnProperty in JavaScript

UnrivaledVenus7746 avatar
UnrivaledVenus7746
JavaScript Flashcards
95 questions

JavaScript Flashcards

JubilantUvarovite avatar
JubilantUvarovite
Use Quizgecko on...
Browser
Browser