Class Homeworks

Scores

Unit Number	My Score
Unit 1	0.9/1
Unit 2	1
Unit 3	0.9/1
Unit 4	1
Unit 5	0.85
Total	4.75/5

Unit 1 - Primitives

Primitives are predefined, lowercase, “Primitives”, which cannot call methods, are a value, and can be different sizes based on what primitive it is. Non primitives are defined by the coder, are uppercase, “Reference types”, which can call methods, can be null, and are all the same size

Homework

2A.

public double purchasePrice() {
  return getListPrice()*(1+taxRate);
}

3A.

public int compareCustomer(Customer other) {
  int comparedCustomer = getName().compareTo(other.getName());
  if(comparedCustomer == 0{
    return getID() - other.getID();
  }else{
  return comparedCustomer
  }
}

Unit 2 - OOP

OOP or object oriented programming is a type of programming language. Classes are a template or blueprint from which objects are created. Objects are instances of a class. Methods are a set of code that perform a specific task. Classes in java can hace data members, methods, constructors, nested classes, and interfaces.

Link to Homework

Unit 3 - Boolean Expressions and If Statements

If/else statements allow you to create a code segment that has checks. If/ElseIf/Else statments can be used to decide different program outputs depending on what the user inputted. Switch statements are also an alternative method to if statements.

Homework

2009 3A.

private int getChargingCost(int startHour, int chargeTime)
{
 int cost = 0;
 for (int x = 0; x < chargeTime; x++){
  cost += this.rateTable[(startHour + x) % 24];
 }
 return cost;
} 

2017 1B.

public boolean isStrictlyIncreasing(){
for (int i = 0; i < digitList.size()-1; i++){
  if (digitList.get(i).intValue() >= digitList.get(i+1).intValue()){
    return false;
   }
}
return true;
}

2019 3B.
public boolean isBalanced(ArrayList<String> delimiters){
 int openCount = 0;
 int closeCount = 0;
 for (String str : delimiters){
  if (str.equals(openDel)){
    openCount++;
  } else{
    closeCount++;
  }
  if (closeCount > openCount){
    return false;
  }
 }
 if (openCount == closeCount){
  return true;
 }
 else{
 return false;
 }
}

Unit 4 - Iteration

Iteration is worth 25% of the test so its pretty important. While loops, for loops, and recursion loops are types of loops. Another example is nested iteration, which can put a loop inside another loop.

Homework

Part 1:

import javax.swing.JOptionPane;
import java.util.Random;

public class NumGuesser {
    Random rand = new Random();
        boolean numCorrect = false;
        String uGuess = "";
        int numGuesses=0;
    
    void run(){
        
        int randNum = rand.nextInt(1000);
        while(numCorrect==false){
            uGuess = JOptionPane.showInputDialog("Guess the number between 1-1000");
            int uGuessNum = Integer.parseInt(uGuess);
            if(uGuessNum>randNum){
                JOptionPane.showMessageDialog(null, "Guess too high, try again. Previous guess: "+uGuessNum);
                numGuesses+=1;
            }else if(uGuessNum<randNum){
                JOptionPane.showMessageDialog(null, "Guess too low, try again. Previous guess: "+uGuessNum);
                numGuesses+=1;
            }else if(uGuessNum==randNum){
                JOptionPane.showMessageDialog(null, "Correct! It took you "+numGuesses+" guesses to get it correct");
                numCorrect=true;
            }
        }
    }
    public static void main(String[] args) {
        NumGuesser ng = new NumGuesser();
        ng.run();
    }
}

Part Two:

Unit 5 - Writing Classes

Classes are a blueprint for instantiating objects. An object is an istance of a class, a class defines an abstract type, methods are the behaviors you get objects to perform. Constructors create the object, are a special method for object instantiation, default constructor has no arguements. Accessor methods are getters and setters, which allow you to get values of variables and return a copy, or edit a variable.

Homework

2021 1A.

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();
}

2021 3A.

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

Unit 6 - Array

Notes: Common errors when making arrays include bound errors, unfilled and uninitialized arrays, when you allocate, or assign a single array variable, but not the whole array. You can use for loops to iterate through an array, by using array.length.

Homework

Link to Homework