In this chapter, we learned about object-oriented programming and why it is better than procedural programming. We started the chapter by exploring classes and learning how to declare them. We also discussed the properties and behavior of classes, and why properties are known as first-class citizens. Then, we had a detailed discussion about data classes, constructors, and how parameterized constructors help us to write clean code. In the last section of this chapter, we covered functions and function overloading. In the next chapter, we will look at some more advanced topics and their implementations.