ZCW-PhoneBook/PhoneBook.java

//JN 2018  
import java.util.*;
public class PhoneBook {
    private TreeMap<String, ArrayList<String>> phoneBook;
    public PhoneBook() {
        phoneBook = new TreeMap<String, ArrayList<String>>(); 
    }
    
    public void add(String name, String phoneNumber) {
        ArrayList<String> input = phoneBook.containsKey(name) ? 
                                  phoneBook.get(name)
                                : new ArrayList<String>();
        input.add(phoneNumber);
        phoneBook.put(name, input);
    }
    
    public void remove (String phoneNumber) {
        ArrayList<String> edit = new ArrayList<String>();
        Set<String> keys = phoneBook.keySet();
        
        for (String key : keys) {
            if (phoneBook.get(key).contains(phoneNumber)) {
                edit = phoneBook.get(key);
                edit.remove(edit.indexOf(phoneNumber));
                phoneBook.put(key, edit);
            }
        }
    }
    
    public void removeEntry(String name) {
        phoneBook.remove(name);
    }
    
    public String lookup(String name) {
        return phoneBook.containsKey(name) ? format(phoneBook.get(name)): "N/A";
    }
    
    public String format(ArrayList<String> numbers) {
        return numbers.toString().replaceAll("[\\[\\]]", "");
    }
    
    public String reverseLookup(String phoneNumber) {
        String output = "";
        Set<String> keys = phoneBook.keySet();
        for (String key : keys) {
            if (phoneBook.get(key).contains(phoneNumber)) {
                output = key;
            }
        }
        return output.equals("") ? "N/A" : output;
    }
    
    public String display() {
       return phoneBook.toString().replaceAll("[{}=,]", "")
                                  .replaceAll("\\[", " - ")
                                  .replaceAll("\\]", "\n");
       
    }
    
    public TreeMap getPhoneBook() {
        return phoneBook; 
    }
}