Intermediate Java (11) - Collections Methods fill

Continued..

import java.util.*;

public class apples{

public static void main(String[] args){

//創建一個array，並轉換為list

Character[] ray = {'p','w','n'};

List<Character> list1 = Arrays.asList(ray);

System.out.println("List is : ");

output(list1);

//反轉array，並打印出list

Collections.reverse(list1);

System.out.println("After reverese");

output(list1);

//創建新的陣列和一個新的list

Character[] newRay = new Character[3];

List<Character> listcopy = Arrays.asList(newRay);

//複製list1內容到listcopy

Collections.copy(listcopy, list1)

Collections.fill(list1, 'X'); → 將list1全部變成X

System.out.println("After filling the list :");

output(list1);

}

private static void output(List<Character> thelist){

for(Character thing:thelist)

System.out.printf("%s ", thing);

System.out.println();

}

}

這是運行時的結果: 

List is :

p w n

After reverese

n w p

Copy of list :

n w p

After filling the list :

X X X