Question

当我尝试打印一些Java代码时，它返回null。我知道我的代码中缺少一些东西，但我不确定是什么。请注意，我对Java相对较新。我几乎肯定它是addGuest方法中的东西。

import java.util.Scanner;

public class PartyParticipants {
int sizeOfList = 3;     
static String[] guestList;      
String hostName;        
String addGuest;
static int Guest;       

Scanner stdIn = new Scanner(System.in);

public PartyParticipants(int size, String host) {

sizeOfList = size;
hostName = host;
}

public static void main(String[] args)
{

    PartyParticipants party = new PartyParticipants(3, "David Beckham");
    party.addGuest("Roberto Baggio");
    party.addGuest("Zinedine Zidane");
    party.addGuest("Roberto Baggio");
    party.addGuest("Johan Cruyff");
    party.addGuest("Diego Maradona");
    party.printParty();

}


private void addGuest(String string) {


for (int i=0; i<sizeOfList; i++)
{

    Guest++;
    }

if (sizeOfList > 3)

{
    System.out.println(Guest + " cannot come to the party. The guest list is    full.");
}

}



public void printParty()

{
{


    System.out.println("Guest list for " + hostName + "'s party:");

    System.out.println(guestList);


}
}
}

Answer 1

您好，您需要初始化您的阵列.. 喜欢做这里的事情

static String[] guestList = new String[sizeOfList ]; 
static int Guest = 0;

并更改addGuest方法

 private void addGuest(String string) 
 {

        if (Guest <= 3)
        {
            System.out.println(Guest + " cannot come to the party. The guest list is    full.");
        }
        else
        {
            guestList[Guest]=string; 
            Guest++;
         }
  }

printParty方法的一个小改动..

public void printParty()    
{
    System.out.println("Guest list for " + hostName + "'s party:");
for(int i=0;i<guestList.length;i++)
    System.out.println(guestList[i]);
}

阅读更多关于java ..

的信息

尝试使用Java将Array添加到Array（打印它们） - 返回NULL

1 个答案: