没有Rails Java程序员如何使用Ruby

　　在列表2中，你将看到相关的Definition类，它类似于Word类-它的exampleSentences属性也没有一个相应的set()方法：

　　列表2.用Java语言实现的一个Definition类

package com.vanward.dictionary;
import java.util.Collection;
public class Definition {
　private Word word;
　private String definition;
　private Collection exampleSentences;
　public Definition(String definition){
this.definition = definition;
this.exampleSentences = new ArrayList();
　}
　public Definition(String definition， Word word) {
this(definition);
this.word = word;
　}
　public Definition(String definition， Word word，Collection exampleSentences) {
this(definition， word);
if(exampleSentences != null){
　this.exampleSentences = exampleSentences;
}
　}
　public String getDefinition() {
return definition;
　}
　public void setDefinition(String definition) {
this.definition = definition;
　}
　public Collection getExampleSentences() {
return exampleSentences;
　}
　public void addExampleSentence(String exampleSentence) {
this.exampleSentences.add(exampleSentence);
　}
　public Word getWord() {
return word;
　}
　public void setWord(Word word) {
this.word = word;
　}
}

　　四、在Ruby中定义类

　　在列表3中，你可以看见以Ruby定义的两个相同的类；然而，列表3看上去与上面相当不同，对不对？