Directions : Complete the following questions, for most of the questions the ret

Question

Directions: Complete the following questions, for most of the questions the return type and name of the method are left out. Give each method a meaningful name and appropriate return type.

Write a method that takes a 2D array of booleans as a parameter and then the method will return the number of elements in that array. You can assume that all of the rows have the same number of elements.

Make a method which returns true if a 2D array of Strings is square. (A square array has the same number of columns as it does rows.)

Create a method that takes a 2D array of doubles as a parameter and makes each element a random number containing the numbers 1 through 10, not including 10. The method should not return anything.

Create a method that takes a 2D array of Strings as a parameter and makes every element in the third column the word “frogurt”. The method should not return anything.

Write in java. These dont take too long so i hope its okay for you to do all 4 methods

Explanation / Answer

1.

class Test
{
public static void main (String[] args)
{
boolean[][] b = new boolean[4][5];

System.out.println("Total Number of elements in array : "+computeTotalElements(b));
}

public static int computeTotalElements(boolean[][] b)
{
  int count = 0;
  
  for(int i = 0;i<b.length;i++) // b.length = rows
  {
   for(int j=0;j<b[i].length;j++)// b[i].length = columns in a row
   {
    count++;
   }
  }
  return count;
}
}

Output:

Total Number of elements in array : 20

2.

class Test
{
public static void main (String[] args)
{
String[][] str = new String[4][5];

System.out.println("Array is Square : "+ifSquare(str));
}

public static boolean ifSquare(String[][] str)
{
  
  if(str.length == str[0].length)// compare length of array(rows) with length of one row
  return true;
  else
  return false;
}
}

Output:

Array is Square : false

3.

class Test
{
public static void main (String[] args)
{
double[][] rand = new double[4][5];

System.out.println("Random numbers of array : ");
randomArray(rand);
}

public static void randomArray (double[][] random)
{
  
     for(int i = 0;i<random.length;i++)
     {
     for(int j = 0;j<random[i].length;j++)
     {
     random[i][j] = 1 + (Math.random() * 9);

     }
     }
    
     for(int i = 0;i<random.length;i++)
     {
     for(int j = 0;j<random[i].length;j++)
     {
     System.out.printf("%.2f ",random[i][j]);

     }
     System.out.println();
     }
   
}
}

Output:

Random numbers of array :
3.74 6.83 1.39 1.50 5.52
8.87 3.57 7.41 4.70 2.85
2.60 7.49 1.08 1.98 4.54
8.82 7.93 8.17 9.90 9.00

4

class Test
{
public static void main (String[] args)
{
String[][] str = new String[][]{{"yogurt","yogurt","yogurt"},{"yogurt","yogurt","yogurt"}};

System.out.println("Changing the third column : ");
update(str);
}

public static void update(String[][] str)
{
  
     for(int i = 0;i<str.length;i++)
     {
     for(int j = 0;j<str[i].length;j++)
     {
     if( j== 2)
     str[i][j] = "frogurt";

     }
     System.out.println();
     }
    
    
     for(int i = 0;i<str.length;i++)
     {
     for(int j = 0;j<str[i].length;j++)
     {
       System.out.print(str[i][j]+" ");
     }
     System.out.println();
     }
   
}
}

Output:

Changing the third column :

yogurt yogurt frogurt
yogurt yogurt frogurt

Do ask if any doubt. Please upvote.

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