CollectionsのツールクラスのaddAll,shuffle
1056 ワード
package com.itheima.demo05.Collections;
import java.util.ArrayList;import java.util.Collections;
/*
*/public class Demo01Collections {
}
import java.util.ArrayList;import java.util.Collections;
/*
- java.utils.Collections , 。 :
- public static boolean addAll(Collection c, T... elements): 。
- public static void shuffle(List> list) : 。
*/public class Demo01Collections {
public static void main(String[] args) {
ArrayList list = new ArrayList<>();
//
/*list.add("a");
list.add("b");
list.add("c");
list.add("d");
list.add("e");*/
//public static boolean addAll(Collection c, T... elements): 。
Collections.addAll(list,"a","b","c","d","e");
System.out.println(list);//[a, b, c, d, e]
//public static void shuffle(List> list) : 。
Collections.shuffle(list);
System.out.println(list);//[b, d, c, a, e], [b, d, c, a, e]
}
}