Question

1. What does the body of your Pair toString method look like?

A. return "LEFT: " + left + " RIGHT: " + right;

B. return System.out.println("LEFT: " + left + " RIGHT: " + right);

C. System.out.println("LEFT: " + left + " RIGHT: " + right);

D. System.out.println("LEFT: " + String + " RIGHT: " + Integer);

2. What does the signature (the first line) of the generic constructor look like in the class?

A. public Pair<U,V>(U u_value, V v_value)

B. public Pair(String U, Integer V)

C. public Pair(U u_value, V v_value)

D. public Pair(U = String, V = Integer)

3. Pick all valid ways to make a new variable of type Pair, with String for both type parameters.

A. Pair<String, String> ss = new Pair(U = "David", V = "J");

B. Pair<String, String> ss = new Pair<>("David", "J");

C. Pair<String, String> ss = new Pair<String, String>("David", "J");

D. Pair<> ss = new Pair<String, String>("David", "J");

4. What method did you use to find the index of "CS1410" in the ArrayList?

A. clear

B. locationOf

C. findValue

D. indexOf

5. Why did the first approach remove and the second approach not remove?

A. In the second case, there was not a named variable holding the reference of the object, so it no longer existed.

B. In the first case, the variable name adding and removing was the same, so it removed. In the second case, there was no variable name, and the name couldn't be compared.

C. Remove works on objects, not on values being the same. In the first case, the reference to the original object was passed in, so it was removed. In the second case, a new object with the same values was passed in, but that is not the same object as in the ArrayList, so it was not removed.

Answer 1

Answer:------------

1. C. System.out.println("LEFT: " + left + " RIGHT: " + right);

2. A. public Pair<U,V>(U u_value, V v_value)

3. B. Pair<String, String> ss = new Pair<>("David", "J");

   C. Pair<String, String> ss = new Pair<String, String>("David", "J");

4. D. indexOf

5. C. Remove works on objects, not on values being the same. In the first case, the reference to the original object was passed in, so it was removed. In the second case, a new object with the same values was passed in, but that is not the same object as in the ArrayList, so it was not removed.