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Provided Code

public class MemberInfo
{
    public MemberInfo(String name, int gradYear, boolean hasGoodStanding) { /* not shown */ }
    public int getGradYear() { /* not shown */ }
    public boolean inGoodStanding() { /* not shown */ }
}

public class ClubMembers
{
    private ArrayList memberList;
    /** Adds new members with given graduation year, all initially in good standing. */
    public void addMembers(String[] names, int gradYear) { /* to be implemented in part (a) */ }
    /** Returns list of graduated members in good standing; removes ALL graduated members. */
    public ArrayList removeMembers(int year) { /* to be implemented in part (b) */ }
}

Part A — 4 Points

Write addMembers, which adds a new MemberInfo for each name in names to memberList, using gradYear and true (initially in good standing). Names can be added in any order.

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public void addMembers(String[] names, int gradYear)
{
    for (String name : names)
    {
        memberList.add(new MemberInfo(name, gradYear, true));
    }
}

Part B — 5 Points

Write removeMembers: remove all members with gradYear <= year from memberList; return an ArrayList of those who were also inGoodStanding().

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public ArrayList removeMembers(int year)
{
    ArrayList graduated = new ArrayList();
    for (int i = memberList.size() - 1; i >= 0; i--)
    {
        MemberInfo m = memberList.get(i);
        if (m.getGradYear() <= year)
        {
            if (m.inGoodStanding())
            {
                graduated.add(m);
            }
            memberList.remove(i);
        }
    }
    return graduated;
}

Common Mistakes to Avoid

for (int i = 0; i < memberList.size(); i++) {
    if (memberList.get(i).getGradYear() <= year) {
        memberList.remove(i);  // next element shifts to i, gets skipped!
    }
}

for (int i = memberList.size() - 1; i >= 0; i--) {
    memberList.remove(i);  // elements to the right of i, not yet checked
}

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