Question

A linked list of Strings named list has been declared and initialized.

Assume that the following code is run on list:
(""A""); (""B""); list.addFirst(""C""); list.addFirst(""D""); list.addLast(""E""); (""F"");
What does list now contain?

Answer 1

The linked list contains the following elements after the specified operations: ["D", "C", "A", "B", "E", "F"]. Elements "C" and "D" are added to the beginning while "E" and "F" are added to the end.

Step-by-step explanation:

The student's question relates to the operations performed on a linked list of Strings. Initially, the linked list is declared and initialized. After following the sequence of operations, which seems to have some missing calls to add method but deducing from the pattern, the result would be: list.add("A"); list.add("B"); list.addFirst("C"); list.addFirst("D"); list.addLast("E"); list.add("F");.

Therefore, the contents of the list after these operations would be: ["D", "C", "A", "B", "E", "F"]. Here's how the linked list is transformed at each step:

1. "A" is added to the list (assuming the missing add method).
2. "B" is added to the list (assuming the missing add method).
3. "C" is added to the beginning of the list.
4. "D" is also added to the beginning, pushing "C" and the others one position back.
5. "E" is added to the end of the list.
6. "F" is added to the list (assuming the missing add method), which would place it at the end.

The specific operations addFirst and addLast dictate where the new elements are placed in the list, whether at the start or at the end, respectively.