一、List

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
// import java.util.*;

public class Hello {

public static void main(String[] args) {

    List<String> list = new ArrayList<String>();
    list.add("hello");
    list.add("World");
    System.out.println(list);

    list.set(1, "vinter");
    System.out.println(list);
    System.out.println(list.size());

    list.remove(0);
    System.out.println(list);
    System.out.println(list.get(0));

    System.out.println(list.contains("vinter"));
    String[] strArray = list.toArray(new String[list.size()]);
    System.out.println(strArray);
    
    String[] aa = {"a","b","c"};
    for(Object item: aa) {
        System.out.println(item);
    }

    List li = Arrays.asList(aa);
    System.out.println(li);
}

}