Classes

  • classes are "blueprints" that we use to instantiate objects
  • classes are an essential aspect of OOP

Anatomy

  • Object
    • state, attributes, behavior
    • represented by an instance in the program
  • Class
    • defines an abstract data type
    • object references: string variable
    • instance variables: attributes, behaviors, data for objects

Functions

  • methods: the action or behavior of an object
  • constructor: special method for object instantiation, sets the initial values for variables, default constructors have no arguments
  • main: tests the class
  • accesser: accesses the values of variables, returns a copy of the variable
  • mutator: changes values of variables

Writing Methods

  • method_definition(Modifiers, Return Type)
  • method_signature(Name, Parameters)
  • method_body(Code)
  • "Object.method()"

Homework: 2021 FRQ 1a, 3a 

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

public void addMembers(String[] names, int gradYear ){ //mutator method - allows modification of grad year but not access to variable
    
    for( String n : names ){
        memberList.add(new MemberInfo( n, gradYear, true) );
    }
    }