Chapter 3: What I learned.......

Chapter 3: What I learned....

Within chapter 3, it detailed primitive AND reference variables and what they do and what they are defined as. The bits representing the variable is the primitive variable, but the bits representing a way to get an object on the heap is known as a reference variable. Also, if you odnt have an object assigned to the reference variable, then it is deemed null. As well as learning about these fun variable types, looking at the dog code (seen below) it taught me what arrays look like and how they should be used. Very useful indeed!

class Dog { 

 String name; 

 public static void main (String[] args) {

 // make a Dog object and access it

 Dog dog1 = new Dog();

 dog1.bark(); 

 dog1.name = “Bart”; 

 // now make a Dog array 

 Dog[] myDogs = new Dog[3]; 

 // and put some dogs in it 

 myDogs[0] = new Dog();

 myDogs[1] = new Dog(); 

 myDogs[2] = dog1; 

 // now access the Dogs using the array references 

 myDogs[0].name = “Fred”; 

 myDogs[1].name = “Marge”; 

 // Hmmmm... what is myDogs[2] name? 

System.out.print(“last dog’s name is “);

 System.out.println(myDogs[2].name); 

 // now loop through the array and tell all dogs to bark 

 int x = 0; 

 while(x < myDogs.length) { 

 myDogs[x].bark(); 

 x = x + 1; 

 } } public void bark() {

 System.out.println(name + “ says Ruff!”);  } 

 public void cat();

 public void chaseCat() 

 }