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Java Java Objects (Retired) Meet Objects Creating Classes

Ayo Ogunlana
Ayo Ogunlana
457 Points

What is the point of Objects and Class in java??

I just want to get an in-depth understanding because Craig said this was the foundation to understanding Java.

5 Answers

Dane Parchment
MOD
Dane Parchment
Treehouse Moderator 11,003 Points

Here hopefully this helps you better understand.

Objects: Objects are literally what you think they are, the programming counterpart of some real-world or abstract objects. Lets say that a car is an object. Well a car has a color, a set mpg, and a manufacturer; also a car can accelerate, decelerate, honk a horn, and turn. Well we can program this as well. We can create a "Car" Object that has a color variable, an acceleration variable, an accelerate method and a decelerate method, etc. etc. What you need to understand is that an object can have states and behaviors in our case the objects states are its: Color, MPG, and Manufacturer while its behaviors are: Accelerating, Decelerating, Turning and Honking!

Class: A class is basically a blueprint for an object, for example:

public class Car {

public int mpg;
public String manufacturer;
public String color;

//This method called a constructer will allow us to create an object of this class in another class (or even in this one)
public Car(int milesPerGallon, String company, String carColor) { 
     this.mpg = milerPerGallon;
     this.manufacturer = company;
     this.color = carColor;
}

public void turnCar() {
//Turns the car left or right
}

public void accelerate() {
//Accelerates the car
}

public void honk() {
//Honks the horn
}

public void decelerate(){
//Decelerates the car
}

}

From that example you can see how we created a class or Blueprint for a car. By using this class we can create car objects in our program. For example:

public class CarLauncher {

public static void main(String [] args) {
     //Create a car object
     Car toyota4Runner = new Car(22, "Toyota", "Black");
     //Create another car object
     Car camaro1969 = new Car(10, "Chevy", "Red");


    //Make the cars accelerate and turn
    toyota4Runner.accelerate();
    toyota4Runner.turn();
    camaro1969.accelerate();
    camaro1969.turn();
}

}

As you can see we created two car objects using the car class as a blueprint!

Hopefully this helps you better understand If you need any more help understanding let me know in the comments!

Ayo Ogunlana
Ayo Ogunlana
457 Points

Thanks, I understand it way better now.

Thanks :)

Brilliant Answer..Got the right explanation for Objects and Classes.. Thanks A lot . Dane Parchment.

Edit: Fixed my name ;) - Dane E. Parchment Jr. (Moderator)

Bryan Martinez
Bryan Martinez
414 Points

Amazing explanation! I was kind of lost but now I understand much better. THank you

Dane Parchment
Dane Parchment
Treehouse Moderator 11,003 Points

Glad to have helped you out. If you are in need any other OOP concept explained, I can definitely do that.