Comparable Interface

Objects that have an ordering are compared using the compareTo() method.

17. Dictionary Entry


The class must implement Comparable.

Dictionary Entry

Say that you are writing a program that acts like a dictionary. A dictionary entry has two instance variables: the word that it defines and the definition.

A class that implements Comparable<T> must implement the method int compareTo( T other ) where T is the type of the class.

Since our Entry implements the Comparable<Entry> interface, it must implement the method int compareTo( Entry other ).

class Entry implements Comparable<Entry>
  private String word;
  private String definition;
  public Entry ( String word, String definition )
    this.word = word;
    this.definition = definition;
  public String getWord()
    return word;

  public String getDefinition()
    return definition;
  public String toString()
    return getWord() + "\t" + getDefinition();
  public int compareTo( Entry other )
   return  ;

Question 17:

When the entries of a dictionary are put in order, does the order depend on the definition?

Should the compareTo() method depend on the definition?

Fill in the blank to complete the compareTo() method.

Hint: use the compareTo() method of the String.