如何从字符串中获取单个单词？

string = "Hello world"
words = string.split()
print(words)  # 输出：['Hello', 'world']

var string = "Hello world";
var words = string.match(/\b\w+\b/g);
console.log(words);  // 输出：['Hello', 'world']

String string = "Hello world";
List<String> words = new ArrayList<>();
String word = "";
for (int i = 0; i < string.length(); i++) {
    char c = string.charAt(i);
    if (Character.isLetterOrDigit(c)) {
        word += c;
    } else if (!word.isEmpty()) {
        words.add(word);
        word = "";
    }
}
if (!word.isEmpty()) {
    words.add(word);
}
System.out.println(words);  // 输出：['Hello', 'world']