ArrayList Practice Worksheet - Insert and Remove Operations

For each question, show what the ArrayList contains after performing all the given operations in order. Write out each step to get full credit.

Question 1

Start with an empty ArrayList called `words`. Perform these operations:

  1. words.add("cat")
  2. words.add("dog")
  3. words.add(1, "bird")
  4. words.remove(0)
  5. words.add("fish")
  6. words.remove("bird")

Show the final contents of the ArrayList:

Final answer: [______, ______]

Question 2

Start with an ArrayList called `nums` containing: `[5, 10, 15, 20]` Perform these operations:

  1. nums.add(2, 12)
  2. nums.remove(Integer.valueOf(10))
  3. nums.add(0, 3)
  4. nums.remove(nums.size()-1)
  5. nums.add(nums.get(1))

Show the final contents of the ArrayList:

Final answer: [______, ______, ______, ______, ______]

Question 3

Start with an ArrayList called `colors` containing: `["red", "blue", "green"]` Perform these operations:

  1. colors.add("yellow")
  2. colors.set(1, "purple")
  3. colors.remove(2)
  4. colors.add(1, "orange")
  5. colors.remove("red")
  6. colors.add(colors.get(0))

Show the final contents of the ArrayList:

Final answer: [______, ______, ______, ______]

Question 4

Start with an ArrayList called `nums` containing: `[2, 4, 6, 8, 10, 12, 14]` Perform these operations:

  1. nums.add(3)
  2. For loop that runs forward through the list: 
    for(int i = 0; i < nums.size(); i++) {
 if(nums.get(i) % 4 == 0) {
     nums.remove(i);
 }
}
  3. nums.add(0, 1)
  4. For loop that doubles each number: 
    for(int i = 0; i < nums.size(); i++) {
 nums.set(i, nums.get(i) * 2);
}

Show the final contents of the ArrayList:

Final answer: [______, ______, ______, ______, ______, ______]