writing classes unit 5

blueprints to instantiate objects
anatomy of a class: object has state, instances, and are represented in an instance
methods and insutructors: behaviors that apply to the object
main method: what the java code runs on
constructors: special method for objecet instantiation
default constructors: no arguements
accessor methods: gives access to the variable value with out to the actual value itself
Mutator method: classes can change the value of a variable without accessing the variable itself
writing a method: method defintion, the signature, the body
void: no reutrn just execute code
static modifiers: class itslef has to be the one that executes the code
"this": refers to constructor being called in , references the object
access modifiers: mainly used for encapsulation and helps to prevent misuse of data public static void main string args
varaibles:local, lock level, parameter

New Vocab

Writing Classes

In Java, there are two main access levels that you will see in this course, private and public
When creating classes, classes should always be declared public since they need to be accessed by other classes

Ex: public class car { blah }

Constructor

You use constructors to create new objects using a class
Constructors are used to set the initial state of an object, which should include initial values for all instance variables
The no-argument constructor executes anytime an object is created and sets any instant variable to their default value
The reason the constructor doesn't return a value is because it's not called directly by your code, it's called by the memory allocation and object initialization code in the runtime. Ex: private int height;

Accessor Methods

An accessor method is a method that is used to return the value of an instance (or static) variable to the user
When naming your method you should always use this format: get[Variable Name] for the name- Getter method Ex:

private int height = 3;

public int getHeight() { return height; }

Mutator Methods

A mutator method is a method that is used to update the value of an instance (or static) variable
Mutator methods set a new value. As such, they are often referred to as setter methods
When creating mutator methods you should always use: set[Variable Name] Ex: private int width = 10;

public void setWidth(int newWidth) { width = newWidth; }

Static Methods/Class Methods

A class method (or static method) is a method of a class that is common to all instances of a class and is not called on any specific object instance
Classes can have both instance variables and static variables, but static methods can only update static variables Ex: private static int getTotalBirds() { return totalBirds; }

Static Variables

Because static methods and variables are available across an entire class, they don’t need to be called on a particular instance of the class. Ex: Skater.getTotalSkaters(); //This will call the getTotalSkaters() method on the Skater class without requiring an instance of the class to be created.

This

"this": refers to constructor being called in , references the object

Access modifiers

mainly used for encapsulation and helps to prevent misuse of data public static void main string args
public, protected, default, private Ex: private static void protected void

accessor tangible

int width = 10;
public int getWidth()
{
  return width;
}

mutator tangible

int height = 3;
public void setHeight(int newHeight)
{
  height = newHeight;
  System.out.println(height);
}

static variables and methods tangibles

class SuperHeroTester
{
    public static void main(String[] args)
    {
        Power speed = new Power("Speed", 10);
        System.out.println("Creating the Flash!");
    
        SuperHero theFlash = new SuperHero("The Flash", speed);
        
        System.out.println("Number of SuperHeroes Created:");
        System.out.println(SuperHero.getNumSuperHeroes());
        
        System.out.println("Creating Shazam!");
        SuperHero shazam = new SuperHero("Shazam", speed);
        
        System.out.println("Number of SuperHeroes Created:");
        System.out.println(SuperHero.numSuperHeroes);
    }


}

2021 FRQ 1a

public int scoreGuess (String guess)
{
    int count = 0 
    for (int = 0, i <= secret.length() - guess.length(), i++)
    {
        if (secret.substring (i, i + guess.length()).equals (guess))
        {
            count++;
        }
    }
    return count * guess.length() * guess.length();
}

2021 FRQ 3a

public void addMembers(String[] names, int gradYear)
{
    for( String n : names )
    {
        MemberInfo newMember = new MemberInfo (n, gradYear, true);
        memberList.add(newMember)
    }   
}