Java Pattern for Word without Spaces

I am wondering what the regex for a word would be, I can seem to find it anywhere? The string I\m trying to match "Loop-num + 5" and I want to extract the "Loop-num" part. I am unsure what the regex would be to do so.

Pattern pattern = Pattern.compile("(loop-.*)");
Matcher matcher = pattern.matcher("5 * loop-num + 5");
if(matcher.find()){
    String extractedString = matcher.group(1);
    System.out.println(extractedString);
}

From this I get: "loop-num + 5"

If you really plan to use the regex to match words (entities comprising just letters, optionally split with hyphen(s)), you need to consider the following regex:

\b\pL+(?:-\pL+)*\b

See regex demo

Explanation:

• \b - leading word boundary
• \pL+ - 1 or more Unicode letters
• (?:-\pL+)* - zero or more sequences of...
  • - - a literal hyphen
  • \pL+ - 1 or more Unicode letters
• \b - trailing word boundary

In Java:

Pattern pattern = Pattern.compile("\\b\\pL+(?:-\\pL+)*\\b", Pattern.UNICODE_CHARACTER_CLASS);
Matcher matcher = pattern.matcher("5 * loop-num + 5");
if(matcher.find()){
    String extractedString = matcher.group(0);
    System.out.println(extractedString);
}

Note: in case words may include digits (not at the starting positions), you can use \b\pL\w*(?:-\pL\w*)*\b with Pattern.UNICODE_CHARACTER_CLASS. Here, \w will match letters, digits and an underscore.