Java - 检索列表中的类型数量

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Set;

public class TypeCount {
    public static void main(String[] args) {
        List<String> list = new ArrayList<>();
        list.add("apple");
        list.add("banana");
        list.add("orange");
        list.add("grape");

        int count = 0;

        for (String s : list) {
            if (s.getClass().isArray()) {
                int length = Array.getLength(s);
                for (int i = 0; i < length; i++) {
                    count++;
                }
            } else {
                count++;
            }
        }

        System.out.println("The number of types in the list is: " + count);
    }
}