如何使数组列表的这个 get 方法更简单？ [复制]

Posted 2023-02-22

【中文标题】如何使数组列表的这个 get 方法更简单？ [复制]

【英文标题】：How do I make this get method for array lists simpler? [duplicate]

【发布时间】：2016-03-23 12:43:14

【问题描述】：

import java.util.*;

public class ChristmasParty

    private Scanner input = new Scanner(System.in);

    public static void main(String[] args)
    
        ChristmasParty cp = new ChristmasParty();
        cp.run();
    

    public void run()
    
        menu();
        addName();
    

    public void menu()
    
        System.out.println("Welcome to the guests lists program");
        System.out.println("Enter a name or enter X to quit");
    

    public void addName()
    
        String nameAdded = "";
        ArrayList<String> guestsLists = new ArrayList<String>();
        do
        
            System.out.print("Enter a name: ");
            nameAdded = input.nextLine();

            guestsLists.add(nameAdded);
            System.out.println("-----------------------------------------------");
            System.out.println(nameAdded + " has been added to the guests list.");

        while(!nameAdded.equals("X"));
        System.out.println("Guests lists:");
        System.out.println("========================");
        System.out.println(guestsLists.get(0));
        System.out.println(guestsLists.get(1));
        System.out.println(guestsLists.get(2));
        System.out.println(guestsLists.get(3));
        System.out.println(guestsLists.get(4));
        System.out.println(guestsLists.get(5));
        System.out.println(guestsLists.get(6));
        System.out.println(guestsLists.get(7));
        System.out.println(guestsLists.get(8));
        System.out.println(guestsLists.get(9));
        System.out.println(guestsLists.get(10));
        System.out.println(guestsLists.get(11));
        System.out.println(guestsLists.get(12));
        System.out.println(guestsLists.get(13));
        System.out.println(guestsLists.get(14));
        System.out.println(guestsLists.get(15));
    
  

您好，我正在尝试编写一个提示用户输入名称的代码，该名称将保存在 arraylists 中，然后一旦用户按“X”退出并退出，它将显示所有列表中的名称。但是如何制作 System.out.println(guestsLists.get());代码更简单，而不是全部输入？

【参考方案1】：

使用增强的for 循环简单地遍历列表：

...
for (String name : guestsLists) 
    System.err.println(name);

...

当您不需要循环内的索引但只想遍历集合时，可以使用for 循环的这种形式。在这些情况下，它比使用显式索引（或使用显式Iterator）更容易阅读（并且代码更少）。

另见https://docs.oracle.com/javase/tutorial/java/nutsandbolts/for.html

【参考方案2】：

输入这段代码：

while(!nameAdded.equals("X"));

System.out.println("Guests lists:");
System.out.println("========================");

for(int i = 0; i < guestsLists.size(); i++)

    System.out.println(guestsLists.get(i));

或

for(String s : guestsLists)

    System.out.println(s);

并删除

之后的所有系统输出

System.out.println("========================");