Java Java Data Structures Efficiency! Using a Map to store Contact Methods

Error: Cannot find symbol..??

Task::-- Modify the addContactMethod method to store the information in the mContactMethods Map.

com/example/model/Contact.java
package com.example.model;

import java.util.Map;
import java.util.Set;
import java.util.HashMap;

public class Contact {
  private String mFirstName;
  private String mLastName;
  private Map<String, String> mContactMethods;

  public Contact(String firstName, String lastName) {
    mFirstName = firstName;
    mLastName = lastName;
    /* This stores contact methods by name
     * eg:  "phone" => "(555) 555-1234"
     */
    mContactMethods = new HashMap<String, String>();
  }

  public void addContactMethod(String method, String value) {
    // TODO: Add to the contact method map
    mContactMethods.add(method, value);
  }

  /**
   * Returns the available contact methods.  eg: phone, pager,
   *
   * @return The name of the contact methods that are available
   */
  public Set<String> getAvailableContactMethods() {
    // FIXME: This should return the current contact method names.
    return null;
  }

  /**
   * Returns the value for the contact method if it exists, 
   *
   * @param methodName  The name of the contact method to look up.
   * @return The name of the contact methods that are available
   */
  public String getContactInfo(String methodName) {
    // FIXME: return the value for the passed in *methodName*
    return null;
  }

  public String getFirstName() {
    return mFirstName;
  }

  public String getLastName() {
    return mLastName;
  }

}

3 Answers

Dino Šporer
Dino Šporer
5,429 Points

task 1 public void addContactMethod(String method, String value) { // TODO: Add to the contact method map mContactMethods.put(method, value); } task 2:

public Set<String> getAvailableContactMethods() { Set<String> values = new HashSet<String>(); for(Map.Entry<String, String> entry : mContactMethods.entrySet() ) { values.add(entry.getKey()); } return values; }

task 3: public String getContactInfo(String methodName) { return mContactMethods.get(methodName); }

Hey Dino,

I appreciate your response. I have a question on task 3:

Why not:---- return methodName.getValue();

Also-- I did task 2 as : Set<String> values = mContactMethods.keySet();
return values; // It worked

Dino Šporer
Dino Šporer
5,429 Points

dont forget to import HashSet

Dino Šporer
Dino Šporer
5,429 Points

I don't think you can call getValue on a string variable. You have a map with keys and values, and you just want to get from value from methodName key... You can look for answer on Stack Overflow, there are many ways to do things right.