我正在学习 Java 的第一学期，我需要帮助从下面的 VotingMachine 类调用 Candidate 类的方法。投票机类已正确编译。感谢大家提供的任何帮助...... 梅赛德斯
import java.util.ArrayList;
/**
* These are the fields for the Voting Machine Class.
*/
public class VotingMachine
{
private ArrayList<String> candidateList;
/**
* The following constructor will establish the Candidate List
*/
public VotingMachine()
{
candidateList = new ArrayList<String>();
}
/**
* This constructor will store the Candidates for the Candidate List
*/
public void setCandidateList()
{
candidateList.add("Darnell Woffard");
candidateList.add("Barack Obama");
candidateList.add("Hillary Clinton");
}
/**
* This method will display the entire Candidate List.
*/
public void printCandidateInfo()
{
for (int index=0; index < candidateList.size(); index++)
{
System.out.println(candidateList.get(index));
}
}
/**
* Method to the number of Candidates in the CandidateList Arraylist.
*/
public int getNumberofFiles()
{
return candidateList.size();
}
/**
* Method to select one candidate by first providing an index number.
*/
public void listFile(int index)
{
if(index >= 0 && index < candidateList.size()){
String filename = candidateList.get(index);
System.out.println(filename);
}
}
/**
* This method will enable a user to remove a candidate.
*/
public void removeFile(int index)
{
if(index >= 0 && index < candidateList.size()){
candidateList.remove(index);
}
}
/**
* This method will add a file to the Candidate List.
*
*/
public void addCandidate(String filename)
{
candidateList.add(filename);
}
//----------
//The Candidate Class:
public class Candidate{
private String name;
private char party;
private String candidateList;
// Add fields
/**
* Fields
* name - Candidate's name, stored in a String
* party - Candidate's political party, stored in a char
* as 'r' for Republican, 'd' for Democrat, and 'i' for Independent
*/
/**
* Constructor
*
* @param anyName - caller inputs Candidate name
* @param anyParty - caller inputs Candidate's party affiliation
* stored as a char
* chars are assigned with single quotes.
*/
public Candidate(String anyName, char anyParty)
{
name = anyName;
party = anyParty;
}
/**
* The method will enable method calls from the Voting Machine Class.
*/
public void main(String candidateList)
{
VotingMachine votingMachine = new VotingMachine();
}
/**
* This method will define the candidates party affiliation.
* public char setParty()
*/
//Complete the three methods and their comments.
/**
* Method to retrieve the Candidate's name for the caller.
* public String getName(String anyName)
*
*/
/**
* Method to retrieve the Candidate's party for the caller.
*
* @return
*/
/**
* Method to change the Candidate's party
*
* @param
*/
最佳答案
实际上我从中得到的是你正在尝试制作一台投票机。 VotingMachine 是这里的主要类，包含不同候选人的信息。所以我们将在votingMachine 类中创建candidate 对象。注意:当我们要创建一个java项目时，弄清楚它的主类和子类是什么，这意味着哪个依赖于哪个。在上面的例子中，类中有关联。首先声明一个ArrayList用于存储候选类的对象。如下所示。
private ArrayList<candidate> candidateList;
/**
* The following constructor will establish the Candidate List
*/
public VotingMachine()
{
candidateList = new ArrayList<String>();
}
现在为了在 ArrayList 中添加新的候选者，我已经修改了你的方法
setCandidate()
作为
public void addNewCandidate(String name, char partySymbol)
{
candidate candid = new candidate(name, partySymbol);// this will call the candidate constructor
candidateList.add(candid);//add that object in ArrayList
}
由于ArrayList存储对象的引用，内置函数int get(int index)将返回对象的引用。要打印该对象的信息或者您可以说值，我们应该将函数定义为 getName()和getParty() 。而不是这个System.out.println(candidateList.get(index));你应该打电话System.out.println(candidateList.get(index).getName());和System.out.println(candidateList.get(index).getParty());在下面的方法中
public void printCandidateInfo()
{
for (int index=0; index < candidateList.size(); index++)
{
System.out.println(candidateList.get(index));
}
}
因此将候选类中的函数定义为
public String getName()
{
return name;
}
/**
* Method to retrieve the Candidate's party for the caller.
*
* @return
*/
public char getParty()
{
return party;
}
以下方法将打印引用信息而不是候选人信息，因此请按上述修改
public void listFile(int index)
{
if(index >= 0 && index < candidateList.size()){
String filename = candidateList.get(index);
System.out.println(filename);
}
}
因为我已经修改了它，
import java.util.ArrayList;
/**
* These are the fields for the Voting Machine Class.
*/
public class VotingMachine
{
private ArrayList<Candidate> candidateList;
/**
* The following constructor will establish the Candidate List
*/
public VotingMachine()
{
candidateList = new ArrayList<>();
}
/**
* This method will store the Candidates for the Candidate List
*/
public void addNewCandidate(String name, char partySymbol)
{
Candidate candid = new Candidate(name, partySymbol);// this will call the candidate constructor
candidateList.add(candid);//add that object in ArrayList
}
/**
* This method will display the entire Candidate List.
*/
public void printCandidateInfo()
{
for (int index=0; index < candidateList.size(); index++)
{
System.out.print(candidateList.get(index).getName());
System.out.println(" " + candidateList.get(index).getParty());
}
}
/**
* Method to the number of Candidates in the CandidateList Arraylist.
*/
public int getNumberofFiles()
{
return candidateList.size();
}
/**
* Method to select one candidate by first providing an index number.
*/
public void listFile(int index)
{
System.out.print(candidateList.get(index).getName());
System.out.println(" " + candidateList.get(index).getParty());
}
/**
* This method will enable a user to remove a candidate.
*/
public void removeFile(int index)
{
if(index >= 0 && index < candidateList.size()){
candidateList.remove(index);
}
}
}
在候选类中，我刚刚添加了上述getName()和getParty()方法..
问候
关于java - 如何从具有数组列表的类调用另一个类的方法？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/20462267/