Find all words with 3 letters with regex

Question

I\'m trying to find all words with 3 letters in a string.
So in this list

cat monkey dog mouse

I only want

cat dog
         


        

Answer 1

1. To match all words with 3 letters in a string, the pattern needs to be "\b[a-zA-Z]{3}\b"

2. The next step would be to compile your pattern.

   Pattern pattern = Pattern.compile("\\b[a-zA-Z]{3}\\b");
   

3. Use a matcher and use the find() and group() methods to print the occurrences

   for (String word : sentence) {
       Matcher matcher = pattern.matcher(word);
       while(matcher.find()) {
           System.out.println(matcher.group());
       }
   }
   

4. Your program should look something like -

   public static void main(String[] args) {
       List sentence = new ArrayList();
       sentence.add("cat");
       sentence.add("monkey");
       sentence.add("dog");
       sentence.add("mouse");
   
       Pattern pattern = Pattern.compile("\\b[a-zA-Z]{3}\\b");
   
       for (String word : sentence) {
           Matcher matcher = pattern.matcher(word);
           while(matcher.find()) {
               System.out.println(matcher.group());
           }
       }
   }