FRQ T1 Test • 3 min read

Initialize Numerical Keypad

public static void initializeKeyboard() {
    int[][] keypad = new int[4][3];;
    for (int i = 0; i < keypad.length; i++)
    {
        for (int j = 0; j < keypad[0].length; j++)
        {
            int val = (3 * i + j + 1);
            keypad[i][j] = val;
        }
    }    
    loop1: for (int i = 0; i < keypad.length; i++)
    {
        for (int j = 0; j < keypad[i].length; j++)
        {
            if (i == 3 && j == 0)
            {
                System.out.print(0);
                System.out.println();
                break loop1;
            }
            System.out.print(keypad[i][j] + " ");
        }
        System.out.println();
    }
}

Reverse an Array

Initialize Random Integers in ArrayList

public static ArrayList randomList(int length, int min, int max) {
    ArrayList<Integer> list = new ArrayList<Integer>();
    for (int i=0; i < length; i++) {
        int randval = (int) ((Math.random() * (max - min + 1)) + min);
        list.add(randval);
    }
    return list;
    
}

Output

public static void main(String[] args)
{
    initializeKeyboard();

    // initialize random ints
    ArrayList<Integer> randomList = randomList(5, 2, 8);
    System.out.println(randomList);
    // System.out.println((int) (Math.random() * (8 - 2 + 1) + 2));
}

main(null);

1 2 3 
4 5 6 
7 8 9 
0
[5, 2, 2, 5, 5]