Extract Hashtags from Text with Regex

function extractHashtags(text) {
  const hashtagRegex = new RegExp(/#(\\w+)/g);
  const matches = text.match(hashtagRegex);
  if (matches) {
    return matches.map(match => match.substring(1)); // Remove '#' prefix
  }
  return [];
}

// Usage examples:
// const tweet = "I love #coding and #javascript. It's a #fun day!";
// console.log(extractHashtags(tweet)); // ["coding", "javascript", "fun"]
// console.log(extractHashtags("No hashtags here.")); // []

How it works: This JavaScript function `extractHashtags` uses a regular expression to find and extract all hashtags from a given text string. The pattern `/#(\\w+)/g` looks for a '#' character followed by one or more word characters (`\w`, which includes letters, numbers, and underscore). The `g` flag ensures all occurrences are found. It then maps the matches to remove the leading '#' from each extracted hashtag. Backslashes within the regex literal (e.g., `\w`) are correctly escaped as `\\w` for JSON string representation.