📄 demoncollections.java
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//使用Collections类中的方法
import java.util.*;
class DemonCollections {
public static void main(String args[]) {
//创建一个包含3个字符串的列表
List list = Collections.nCopies(2,"dog");
//创建一个数组列表
ArrayList arrayList = new ArrayList(list);
System.out.println("The initial list is "+arrayList);
list = null;//将列表清空
//将"cat"字符串添加进列表
Collections.fill(arrayList,"cat");
System.out.println("After filling cat,the list is " + arrayList);
//向列表中添加3个新元素
arrayList.add("horse");
arrayList.add("rabbit");
arrayList.add("dog");
System.out.println("After adding new elements,the list is \n" + arrayList);
//将列表中的元素随机排列
Collections.shuffle(arrayList);
System.out.println("After shuffling,the list is \n" + arrayList);
//查找列表中的最小元素和最大元素
System.out.println("The minimum element in the list is " + Collections.min(arrayList));
System.out.println("The maximum element in the list is " + Collections.max(arrayList));
//给列表排序
Collections.sort(arrayList);
System.out.println("The sorted list is\n" + arrayList);
//检索列表
System.out.println("The search result for dog is " + Collections.binarySearch(arrayList,"dog"));
}
}
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