HashSet的代码示例

可以参考以下代码示例：

import java.util.HashSet;

public class HashSetExample {
    public static void main(String[] args) {
        HashSet<String> set = new HashSet<>();

        // add elements to set
        set.add("apple");
        set.add("banana");
        set.add("orange");

        // check if an element is in the set
        boolean containsApple = set.contains("apple");
        System.out.println("Contains apple? " + containsApple);

        // remove an element from the set
        set.remove("banana");

        // iterate over the set
        System.out.println("Elements in set:");
        for (String element : set) {
            System.out.println(element);
        }

        // get the size of the set
        int size = set.size();
        System.out.println("Size of set: " + size);
    }
}