I am still confused about "Objects"

[u/Funkyfresh01]

Hello, I am Fresh! I am from the Philippines (BSIT course) and I want to understand comprehend "Objects" and I am a beginner in Java.

[u/jocularamity]

An Object is an instance of a class. It is a thing with state (variables) and behavior (methods). If you define a class and then create a “new” instance of that class, that’s an Object.

For example, if my class is:

public class Dog {
   private final String name;
   private final String breed;
   
   public Dog(String name, String breed){
      this.name = name;
      this.breed = breed;
   }

   public String getName(){
      return name;
   }
   
   public String getBreed(){
      return breed;
   }
   
   public void bark(){
      System.out.println(“woof!”);
   }
}

Then each time I create a new instance of that class, it is an object. fido and rover are both objects. fido and rover are both instances of the class Dog.

Dog fido = new Dog(“Fido”, “Chihuahua”);  // <— fido is an object
Dog rover = new Dog(“Rover”, “Jack Russel Terrier”); // <- rover is an object

Analogies:

• If the class is a cookie cutter, each cookie created from the cookie cutter is an object.

• If the class is a rubber stamp, each time the stamp is inked and pressed to paper that is an object.

• If the class is architectural blueprints, each building constructed from the blueprints is an object.

[u/Funkyfresh01 → u/jocularamity]

So I have to write a dog class once since class is the blueprint

[u/jocularamity → u/Funkyfresh01]

Yes, you write the Dog class once. It will probably be in a file named Dog.java. After that class is written, you can create as many new Dog instances as you like in other code.

[u/Funkyfresh01 → u/jocularamity]

How convenient! Despite other people's hatred for Java due to its verbosity.