CS3401 Quiz 1 - No answers yet will update

Question 1 (5 points)

 

How many times is the following factorial method invoked for complicatedSum(6)?

---

public int complicatedSum(int n) {

    if (n <= 3)

        return n;

    else if (n % 3 == 0)

        return n * 3 + complicatedSum(n-1);

    else if (n % 3 == 2)

        return n * 2 + complicatedSum(n-1);

    else

        return n + complicatedSum(n-1);

}

---

Question 1 options:

	6
	5
	4
	3

Save

Question 2 (5 points)

 

What does recursiveString("abcd") return if that method is defined by the following?

---

  public String recursiveString(String str) {
      if (str.length() < 2)
          return str;
      return recursiveString(str.substring(1)) +
                          str.substring(str.length()-1);
  }

---

Question 2 options:

Save

Question 3 (5 points)

 

What does the following method compute? Assume the method is called initially with i = 0.

---

public int recursiveEx2(String a, char b, int i) {

    if (i = = a.length( ))

        return 0;

    if (b = = a.charAt(i))

        return recursiveEx2(a, b, i+1) + 1;

    return recursiveEx2(a, b, i+1);

}

---

Question 3 options:

	The length of String a
	the length of String a concatenated with char b
	the number of times char b appears in String a
	the char which appears at location i in String a

Save

Question 4 (5 points)

 

What type of argument can the following generic method be passed?

---

public static <E extends Number> void displayArray(E[] array) {

     for (E element : array)

         System.out.println(element);

}

---

Question 4 options:

	an array whose element type is Object
	an array whose element type is int
	an array whose element type is Integer
	an array whose element type is any superclass of Number

Save

Question 5 (5 points)

 

True or False: ArrayList<Comparable> is a subclass of ArrayList<E extends Date>

Question 5 options:

	True
	False

Save