Hack 1

import java.util.ArrayList;
import java.util.Scanner;

public class NumberListDemo {
    private ArrayList<Integer> numbers = new ArrayList<>();

    // Method to add a number to the list
    public void addNumber(int num) {
        numbers.add(num);
    }

    // Method to retrieve a number from the list by its index
    public int getNumberAtIndex(int idx) {
        if (idx >= 0 && idx < numbers.size()) {
            return numbers.get(idx);
        } else {
            return -1; // Return -1 if the index is out of bounds
        }
    }

    public static void main(String[] args) {
        NumberListDemo demo = new NumberListDemo();
        Scanner inputScanner = new Scanner(System.in);

        // Adding some sample numbers to the list
        demo.addNumber(101);
        demo.addNumber(102);
        demo.addNumber(103);

        System.out.println("Please provide an index to retrieve the number: ");
        int userInput = inputScanner.nextInt();

        int retrievedNumber = demo.getNumberAtIndex(userInput);

        if (retrievedNumber != -1) {
            System.out.println("Number at index " + userInput + ": " + retrievedNumber + ". Well done!");
        } else {
            System.out.println("Oops! That's an invalid index. Please try again.");
        }

        inputScanner.close();
    }
}

NumberListDemo.main(null);

Hack 2

import java.util.Random;
import java.util.Scanner;

public class ExponentChallenge {
    public static void main(String[] args) {
        Scanner userInput = new Scanner(System.in);
        Random randGenerator = new Random();

        int lowerLimit = 1;
        int upperLimit = 10;
        int randomBase = randGenerator.nextInt(upperLimit - lowerLimit + 1) + lowerLimit; // generates random base number
        int power = randGenerator.nextInt(5) + 1; // generates random power

        System.out.println("Try to guess the base number and its power for a number between " + lowerLimit + " and " + upperLimit + " (Clues will be given):");
         
        int tries = 0;
        while (true) {
            System.out.println("Input your guess for the BASE number: ");
            int basePrediction = userInput.nextInt();

            System.out.println("Input your guess for the POWER: ");
            int powerPrediction = userInput.nextInt();

            if (basePrediction == randomBase && powerPrediction == power) {
                System.out.println("Well done! You've correctly identified the base number and its power.");
                break;
            } else {
                tries++;
                System.out.println("That's not right. Here are some clues: ");
                System.out.println("Clue 1: The base number lies between " + lowerLimit + " and " + upperLimit);
                System.out.println("Clue 2: The power is " + power);
                System.out.println("Number of tries: " + tries);
            }
        }

        userInput.close();
    }
}

ExponentChallenge.main(null);

Input your guess for the POWER:

Hack 3

import java.util.Scanner;

public class DataRetriever {
    private int numValue;
    private boolean flagValue;
    private String textValue;
    private double floatNumValue;

    public DataRetriever(int numValue, boolean flagValue, String textValue, double floatNumValue) {
        this.numValue = numValue;
        this.flagValue = flagValue;
        this.textValue = textValue;
        this.floatNumValue = floatNumValue;
    }

    public static void main(String[] args) {
        // Create a sample instance for demonstration
        DataRetriever instance = new DataRetriever(420, false, "Hello, World!", 3.141592653589);
        Scanner inputScanner = new Scanner(System.in);

        // Prompt the user to choose a data type and display the corresponding value
        System.out.println("Choose the data type (int, boolean, string, double): ");
        String chosenType = inputScanner.nextLine();

        // Display the value based on the chosen data type
        switch (chosenType.toLowerCase()) {
            case "int":
                System.out.println("Integer Value: " + instance.numValue);
                break;
            case "boolean":
                System.out.println("Flag Value: " + instance.flagValue);
                break;
            case "string":
                System.out.println("Text Value: " + instance.textValue);
                break;
            case "double":
                System.out.println("Floating Number Value: " + instance.floatNumValue);
                break;
            default:
                System.out.println("Data type not recognized.");
        }

        inputScanner.close();
    }
}

DataRetriever.main(null);

Choose the data type (int, boolean, string, double): 
Data type not recognized.

Hack 4

public class Individual {
    private String completeName;

    public Individual(String completeName) {
        this.completeName = completeName;
    }

    public String extractFirstName() {
        StringBuilder fName = new StringBuilder();
        // Loop through each character until a space is found, which indicates the end of the first name
        for (int index = 0; index < completeName.length(); index++) {
            char character = completeName.charAt(index);
            if (character == ' ') {
                break; 
            }
            fName.append(character);
        }
        return fName.toString();
    }
     
    public String extractLastName() {
        StringBuilder lName = new StringBuilder();
        boolean spaceDetected = false;
        for (int index = 0; index < completeName.length(); index++) {
            char character = completeName.charAt(index);
            if (spaceDetected) {
                lName.append(character);
            }
            if (character == ' ') {
                spaceDetected = true;
            }
        }
        return lName.toString();
    }

    public static void main(String[] args) {
        // Sample name for demonstration
        Individual individual = new Individual("Kaiden Do");

        String fName = individual.extractFirstName();
        String lName = individual.extractLastName();

        System.out.println("First Name: " + fName);
        System.out.println("Last Name: " + lName);
    }
}

Individual.main(null);

First Name: Kaiden
Last Name: Do

Overall, I thought the hacks were pretty good for helping solidify the Unit 2 content from the lesson. I felt that the second hack was easily the hardest one, simply because it was difficult to get the random part of it working properly.

Unit 2 Hacks • 11 min read

Description

Hack 1

Hack 2

Hack 3

Hack 4