why i cannot pass??

public class Solution { public static void main(String[] args) throws Exception { //在此编写你的代码 HashSet<String> list = new HashSet<String>(); list.add("西瓜"); list.add("香蕉"); list.add("樱桃"); list.add("梨"); list.add("哈密瓜"); list.add("黑莓"); list.add("人参"); list.add("草莓"); list.add("鸢尾花"); list.add("土豆"); for(String t :list){ System.out.println(t); } } }

应为set.add("");

I might be mistaken, but as far as I know, you can't declare and initialize a Set the way you did in lines 12ff.

HashSet<String> set = new HashSet<String>(){ someValue, anotherValue, andSoOn...}

Edit: I just found this discussion, the second answer shows your syntax (with the double braces {{ add("") }}, so it might just work. Sorry, I didn't know that. However, one comment mentions that this solution is a bit "hacky" because it's "creating an anonymous inner subclass of HashSet with a static initialisation section that calls the add() method" - which is way above my head, I honestly don't have a clue what all of that means. :) So, maybe you should try the more common and boring solution:

// First create the new Set:
HashSet<String> set = new HashSet<String>();
//then add values directly to the created set:
set.add("西瓜");
set.add("香蕉");
// ...