CSAwesome2: AP CSA Java 2025+

public class C1
{
   private int num;
   private String name;

   public C1(int theNum)
   {
      num = theNum;
   }

   public C1(String theName)
   {
      name = theName;
   }
   // other methods not shown
}

public class C2 extends C1
{
// methods not shown
}

Possible constructors
I.   public C2 () { }
II.  public C2 (int quan) {super (quan); }
III. public C2 (String label) { super(label); }

public static void sort(int[] a)
{
   int maxCompare = a.length - 1;
   int savedIndex = 0;
   int numSteps = 0;
   int temp = 0;

   for (int i = maxCompare; i > 0; i--)
   {
      savedIndex = i;

      for (int j = i - 1; j >= 0; j--)
      {
        /* missing code */
      }

     temp = a[i];
     a[i] = a[savedIndex];
     a[savedIndex] = temp;
   }
}

int[][] matrix = new int[2][3];

public static void changeMatrix(int[][] matrix )
{
   for (int row = 0; row < matrix.length; row++)
      for(int col = 0; col < matrix[row].length; col++)
         if(row==col)
            matrix[row][col] = Math.abs(matrix[row][col]);
}

int a = 5, b = 2, temp;

for (int i=1; i<=4; i++)
{
   temp = a;
   a = i + b;
   b = temp – i;
}

public static int mystery(int n)
{
   if (n == 0)
      return 1;
   else
      return 3 * mystery (n - 1);
}

for(int i = 0; i < 3; i++)
{
   for(int j = 1; j <= 7; j++)
      System.out.println("*");
}

public static void conditionTest(int num1, int num2)
{
   if ((num1 > 0) && (num2 > 0))
   {
      if (num1 > num2)
         System.out.println("A");
      else
         System.out.println("B");
   }
   else if ((num2 < 0) && (num1 < 0))
   {
      System.out.println("C");
   }
   else if (num2 < 0)
   {
      System.out.println("D");
   }
   else
   {
      System.out.println("E");
   }
}

String s1 = "Hi There";
String s2 = s1;
String s3 = s2;
String s4 = s1;
s2 = s2.toUpperCase();
s3 = s3.toLowerCase();
s4 = null;

String s = "Computer Science is fun!";
String s1 = s.substring(0,8);
String s2 = s1.substring(2);
String s3 = s2.substring(0,3);
System.out.println(s3);

public class Book
{
    // code for class
}

public class Dictionary extends Book
{
    // code for class
}

public static int mystery(String str)
{
   if (str.length() == 0)
       return 0;
   else
   {
      if (str.substring(0,1).equals("x"))
          return 1 + mystery(str.substring(1));
      else
          return mystery(str.substring(1));
   }
}

Animal[] a = { new Cat(), new Cow(), new Dog(), new Pig(), new Bird() }

Animal that has a method speak() which returns "Awk".
Bird doesn’t have a speak method
Dog has a speak method that returns "Woof"
Pig doesn’t have a speak method
Cow has a speak method that returns "Moo"
Cat has a speak method that returns "Meow"

public static void test(int[] a, int y)
{
   if (a.length > 1)
      a[1] = a[1] * 2;
   y = y * 2;
}

int[] s = {3,4};
int b = 4;
test(s,b);

I.  Insertion sort takes longer when the array is sorted in ascending order and
    you want it sorted in descending order.
II.  Mergesort uses recursion.
III.  Selection sort takes less time to execute if the array is already sorted
      in the correct order.

private int[] arr;

public int mystery(int low, int high, int num)
{

   int mid = (low+high) / 2;

   if (low > high)
   {
      return -1;
   }
   else if (arr[mid] < num)
   {
      return mystery(mid +1, high, num);
   }
   else if (arr[mid] > num)
   {
      return mystery(low, mid - 1, num);
   }
   else
      return mid;
}