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Java Java Data Structures - Retired Efficiency! Add tags to a course

Posted by iclick
iclick
10,945 Points

Finally, for this task, let's modify the hasTag method and check to see if the tag has been added to the mTags set.

I am having problem with the last task. I need some idea. I can't figure it out :(

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

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


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

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

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

  public boolean hasTag(String tag) {
    // TODO: Return whether or not the tag has been added
    if (!mTags.contains(tag)) {
      return false;
    }
    return true;
  }

  public String getTitle() {
    return mTitle;
  }

}

2 Answers

Florian Tönjes
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Florian Tönjes
Full Stack JavaScript Techdegree Graduate 50,856 Points
Florian Tönjes
.a{fill-rule:evenodd;}techdegree seal-36
Florian Tönjes
Full Stack JavaScript Techdegree Graduate 50,856 Points

Irene,

your code is alright. Make sure you keep the code from the former steps. You are stuck at step three now. To have come this far, you had to have the 'addTags' method already implemented. It is missing from your code now.

Implement the 'addTags' method again and you'll be fine.

Kind Regards, Florian

Harley Barrier
Harley Barrier
1,068 Points
Harley Barrier
Harley Barrier
1,068 Points

Outside of that the only problem I ran into was that you have return true; and return false; backwards.

Stephen Wall
PLUS
Stephen Wall
Courses Plus Student 27,294 Points
Stephen Wall
Stephen Wall
Courses Plus Student 27,294 Points

You are missing the "addTags" method, which allows you to add a list of tags, instead of one at a time: 

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

You just want to see if the set contains the tag we are looking for, sets provide a boolean method for us to use aptly named "contains"! You can accomplish the same goal by returning it on one line like so:

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