JAVA -在字符串中每隔两个单词后添加一个逗号？

public class StringCommaAdder {
    public static void main(String[] args) {
        String input = "This is a sample string for testing";
        String output = addComma(input);
        System.out.println(output);
    }

    public static String addComma(String input) {
        // 使用正则表达式将字符串按照空格分割成单词数组
        String[] words = input.split("\\s+");
        StringBuilder result = new StringBuilder();

        // 遍历单词数组，每隔两个单词后添加逗号
        for (int i = 0; i < words.length; i++) {
            result.append(words[i]);
            if ((i + 1) % 2 == 0 && i != words.length - 1) {
                result.append(",");
            } else {
                result.append(" ");
            }
        }

        return result.toString();
    }
}