7. Refer to the following code: private int[] arr; //precondition: arr.length >

Question

7. Refer to the following code:

private int[] arr;

//precondition: arr.length > 0
public void mystery()
{
     int s1 = 0;
     int s2 = 0;

     for (int k = 0; k < arr.length; k++)
    {
          int num = arr[k];
          if ((num > 0) && (num % 2 == 0))
                s1 += num;
          else if (num < 0)
                s2 += num;
      }
      System.out.println (s1);
      System.out.println (s2);

Which of the following best describes the value of s1 output by the method mystery?

Question 7 options:

The sum of all values greater than 2 in arr

The sum of all positive values in arr

the sum of all positive odd values in arr

The sum of all positive even values in arr

The sum of all values less than 2 in arr

8. Consider the static method selectSort shown below. Method selectSort is intended to sort an array into increasing order; however, it does not always work as intended.

//precondition: numbers.length >0
//postcondition: numbers is sorted in increasing order
public static void selectSort(int[] numbers)
{
      int temp;
Line1: for (int j = 0; j < numbers.length - 1; j++)
           {
Line 2:     int pos = 0;
Line 3:     for (int k = j + 1; k < numbers.length; k++)
                 {
Line 4:             if (numbers[k] < numbers [pos])
                         {
Line 5:                      pos = k;
                         }
                  }
                  temp = numbers[j];
                  numbers[j] = numbers[pos];
                  numbers[pos] = temp;
           }
}

Which of the following changes should be made so that selectSort will work as intended?

Question 8 options:

Line 2 should be changed to

int pos = j;

Line 5 should be changed to

k = pos;

Line 4 should be changed to

if (numbers[k] > numbers[pos])

Line 1 should be changed to

for (int j = 0; j < numbers.length - 2; j++)

Line 3 should be changed to

for (int k = 0; k < numbers.length; k++)

9. Consider the following declaration.

int valueOne, valueTwo;

Assume that valueOne and valueTwo have been initialized. Which of the following evaluates to true if valueOne and valueTwo contain the same value?

Question 9 options:

valueOne == valueTwo

valueOne.compareTo((Object) valueTwo) == 0

valueOne.equals(valueTwo)

valueOne.compareTo(valueTwo) == 0

valueOne.equals((Object) valueTwo)

10. When designing classes, which of the following would be the best reason to use inheritance?

Question 10 options:

Inheritance allows the creation of a subclass that can use the methods of its superclass without rewriting the code for those methods.

Inheritance reduces the number of polymorphic structures encapsulated in applications.

Inheritance guarantees that the applications will compile and execute much more quickly.

Inheritance allows for data encapsulation, while noninherited classes do not allow for data encapsulation.

Inheritance allows you to write applications that require fewer base and super classes.

11. Assume that the methods f and g are defined as follows.

public int f(int x)
{
     if (x <= 0)
     {
          return 0;
     }
    else
    {
         return g (x - 1);
    }
}

public int g(int x)
{
      if (x <=0 )
       {
             return 0;
       }
       else
       {
             return (f(x - 1) + x);
       }
}

What value is returned as a result to the call f(6)?

Question 11 options:

9

0

12

6

3

The sum of all values greater than 2 in arr

The sum of all positive values in arr

the sum of all positive odd values in arr

The sum of all positive even values in arr

The sum of all values less than 2 in arr

Explanation / Answer

ANSWER 7: Here from the code it is clear that option(D) is correct becuase it is checking in if for greater than zero number and even number also.

ANSWER 8: Here option(A) will be correct no doubt.

ANSWER 9: Here option(C) will be correct because .equals() method used for content comparision and == is used for reference comparision in java

ANSWER 10: Here also option(A) is correct because we cam use parent class method in inheritence.

ANSWER 11: This method will return 9 so option(A) is correct here.

Related Questions

Navigate

• Browse (All)
• Browse 7
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.