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Java Java Data Structures Efficiency! Add tags to a course

Posted by micahgreen
micahgreen
1,027 Points

Having trouble with the "hasTag" method in Course.java.

I have tried several different solutions for the "hasTag" method problem, but none have worked. I have used the .contains method from the Set class and also the .contains method. Most recently, as you'll see below, I tried using an if-else statement and that didn't work. I deleted the else part of the statement and decided to give up and ask the forum. The current answers in the forum didn't help me with question 3 of the problem. Can someone help me find a good solution? I've gotten this far in the java training without getting stuck and finally hit a road block :( Thanks for any help you can give!

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

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

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(tag);
  }

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

  public boolean hasTag(String tag) {
    // TODO: Return whether or not the tag has been added
    if (mTags.contains(tag)) {
     System.out.println("Tag already exists");

    }
    return false;

  }

  public String getTitle() {
    return mTitle;
  }


}

1 Answer

Craig Dennis
STAFF
Craig Dennis
Treehouse Teacher
Craig Dennis
Craig Dennis
Treehouse Teacher

What if you return the result of that expression?

micahgreen
micahgreen
1,027 Points

This seemed to fix it: 

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

Although I'm sure there's a much better way. I have a long way to go to truly understand the syntax. Thanks for your help Craig! I really enjoy your teaching.

Sincerely, Micah Green

Craig Dennis
Craig Dennis
Treehouse Teacher
Craig Dennis
Craig Dennis
Treehouse Teacher

Remember you can return the result of an expression like so:

return mTags.contains(tag);
micahgreen
micahgreen
1,027 Points

Even better! Thanks again Craig!