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Java Java Data Structures Efficiency! Add tags to a course

modify hasTag

I'm confused on what I need to return

package com.example.model;

import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class Course {
  private String mTitle;
  private Set<String> mTags;

  public Course(String title) {
    mTitle = title;
    // TODO: initialize the set mTags
    mTags = new HashSet<String>();

  public void addTag(String tag) {
    // TODO: add the tag
    mTags.add(new String(tag));

  public void addTags(List<String> tags) {
    // TODO: add all the tags passed in
    for (String allTags : tags){
      mTags.add(new String(allTags));

  public boolean hasTag(String tag) {
    // TODO: Return whether or not the tag has been added
    return false;

  public String getTitle() {
    return mTitle;


1 Answer

What this is asking you to check is if your set "mTags" contains the tag that is passed in. Hmm....

  public boolean hasTag(String tag) {
    return mTags.contains(tag);

This will return either true or false whether or not the tag that you're searching for is in mTags.

Great job on the rest of the challenge!