ZCW-PhoneBook/PhoneBook.java

 
import java.util.*;
/**
 * Created by leon on 1/23/18.
 */
public class PhoneBook {
    
    Map<String, ArrayList<String> > entries = new HashMap<String, ArrayList<String>>();
    
    public void add (String name, String phoneNumber){
        ArrayList<String> pn = new ArrayList<String>();
        pn.add(phoneNumber);
        this.entries.put(name, pn);
    }
    
    public void addNumber(String name, String phoneNumber){
        for(Map.Entry<String, ArrayList<String>> entry: this.entries.entrySet()){
            if(name.equals(entry.getKey())){
                entry.getValue().add(phoneNumber);
                break;
            }
        }    
    }
    
    public void remove(String name, String phoneNumber){
    }
    
    public void removeRecord(String name){
        this.entries.remove(name);
    }
    
    
    
    public void lookUp(String name){
        System.out.print(this.entries.get(name));
    }
    
    public String reverseLoopup(String phoneNumber){
        String name = "No Records...";
        for(Map.Entry<String, ArrayList<String>> entry: this.entries.entrySet()){
            
            for(String pn : entry.getValue()){
                if(pn.equals(phoneNumber)){
                    name = entry.getKey();
                }
            }
            
        }
        return name;
        
    }
    
    
    public void display() {
        StringBuilder sb = new StringBuilder();
        
        for(Map.Entry<String, ArrayList<String>> entry :this.entries.entrySet()){
            sb.append(entry.getKey());
            sb.append(" - ");
            sb.append(entry.getValue());
            sb.append("\n");
        }
        
        System.out.print(sb.toString());
    }
   
    
    
}