Java - Class and Object confusion

[puspandahal]

class Dog {   // this is Class
  
  int age;

	public Dog(int dogsAge) {  // what we call this line?
    
    dogsAge = age;               // why are we defining dogsAge = age; ?
  
  }

public void bark(){                              // what we call this line?
  
  System.out.println("woof!");
}

  public void run(int feet){
    System.out.println("your dog ran " + feet +" feet!");
    
  }
 
	public static void main(String[] args) {
    
    Dog spike = new Dog(5);
    spike.bark();
    spike.run(35);
   
	}

sorry if this sounds stupid. I never got about class, object. if someone can explain, It would really be grateful.

[stetim94]

public Dog(int dogsAge) { // what we call this line?

its the constructor, its a method but its automatically called when you create an instance of your class.

here:

Dog spike = new Dog(5);

you create an instance named spike, which will cause the constructor to execute.

age is instance variable, it has a different value for each instance, so when we create a new Dog(argument); we pass an argument (5 for spike) to the constructor, so we can set the instance variable.

public void bark(){ // what we call this line?

a public method which doens’t return anything (void) named bark

[tristanlewis]

One thing I don’t understand about this is why do you create an instance of a Dog (spike) within the Dog class? I thought the class was the template.

(Or maybe its just how I’m interpreting this code)

[stetim94]

Ideally we should have a Main and Dog class.

Java main method is the entry point of any java program. Its syntax is always public static void main(String[] args)

even though its in a class, main method is special