Java集合-Collections工具类

Java Collections工具类

• java.util.Collections;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Test {
    public static void main(String[] args) {
        List<String> list = new ArrayList<>();
        for(int i = 0; i < 5; i++){
            list.add("x" + i);
        }
        System.out.println(list); //[x0, x1, x2, x3, x4]

        Collections.shuffle(list);
        System.out.println("随机排序:" + list); 

        Collections.reverse(list);
        System.out.println("逆序:" + list);

        Collections.sort(list);
        System.out.println("顺序:" + list);

        System.out.println(Collections.binarySearch(list, "x2")); //2
        
        Collections.fill(list,"something");
        System.out.println(list);  //[something, something, something, something, something]
    }
}