Programming Problems using ArrayList

You will submit this assignment using git and Github.

Instructions

Go to the URL given in class; accept the assignment and create a repository.

Clone the repository to your computer.

# Change directory to your workspace for Programming 1 labs:
cmd> cd someplace/workspace
# Clone the project. This will clone arraylistlab-yourlogin into a
# new directory named arraylab.
cmd> git clone  https://github.com/OOP2018/arraylistlab-yourlogin.git  arraylistlab

Complete the problems below. Periodically “commit” your work to your local repository.
Test your work. Review your code. Is it well formatted and easy to read?
Push the finished lab to Github:
```
cmd> git push
```
Ask the instructor or TA to review your code! You might get some good ideas for improving it. You can “push” again (and again) if you make changes.

Problem 1: ListExplorer.java

Complete these methods. The Javadoc comments in code describe what each method should do.

printList(ArrayList<String> list) prints contents of the list on the console like this:
```
 list = { first, second, third, fourth }
```
If the list is empty, then print:
```
 list = { }
```
Print only 10 elements per line. Add newline after each 10th element.
append(String value, ArrayList<String> list) append value to the list. Don’t print anything.
insert(String value, int index, ArrayList<String> list) insert value at position index in the list. If successful, don’t print anything. If index is too large then print a message like: 8 is too large. Last index is 5.
remove(int index, ArrayList<String> list) remove one element from list at index and print it on the console. For example:
```
 Removed Banana
```
If the index is too large, then print (for example):
```
 8 is too large. Last index is 5.
```
find(String value, ArrayList<String> list) find value in the list and print index of its position. For example find("Banana",list) might print: Banana is element 5. If it is not in list, print: Banana not in list.
Run the application. Use the console dialog to see what the ArrayList methods do.

Example of running program:

a value       - append value to the end of list
i index value - insert a value into list at index (integer)
d index       - delete element at index
f value       - find value in the list, print its location
p             - print the list
q             - quit
?             - print this menu again
Input: p
list = { }
Input: a apple
Input: a orange
Input: p
list = { apple, orange }
Input: i 1 fig
Input: p
list = { apple, fig, orange }
Input: d 0
Removed apple
Input: p
list = { fig, orange }
Input: a apple
Input: p
list = { fig, orange, apple }
Input: f orange
orange  is element 1
Input: q

Problem 2: Code Improvement

ArrayList implements the List interface. That means ArrayList is a kind of List. All kinds of List have the same methods, so the ListExplorer methods should work with any List – not just ArrayList.

When you use a List as method parameter, it is more flexible to use the Interface type (List) instead of a specific class name (ArrayList). In this problem, we should use “List” instead of “ArrayList” as parameter type. For example:

public void findStudent( List<String> students, String name )

is better than:

public void findStudent( ArrayList<String> students, String name )

In all the methods that have ArrayList<String> as a parameter, change the parameter type to List<String>. (But don’t change the local list variable in consoleDialog.)
Add the import import java.util.List;.
Verify that the program still works correctly.

Any method that expects a “List” as parameter will accept an “ArrayList” object as the actual value when you invoke the method. It is a form of polymorphism.