title: Check if letter is emoji
body: <p>I want to check if a letter is a emoji. I've found some similiar questions on so and found this regex: </p>
  
  <pre><code>private final String emo_regex = "([\\u20a0-\\u32ff\\ud83c\\udc00-\\ud83d\\udeff\\udbb9\\udce5-\\udbb9\\udcee])";
  </code></pre>
  
  <p>However, when I do the following in a sentence like: </p>
  
  <pre><code>for (int k=0; k&lt;letters.length;k++) {    
      if (letters[k].matches(emo_regex)) {
          emoticon.add(letters[k]);
      }
  }
  </code></pre>
  
  <p>It doesn't add any letters with any emoji. I've also tried with a <code>Matcher</code> and a <code>Pattern</code>, but that didn't work either. Is there something wrong with the regex or am I missing something obvious in my code?</p>
  
  <p>This is how I get the letter:</p>
  
  <pre><code>sentence = "Jij staat op 10 "
  String[] letters = sentence.split("");
  </code></pre>
  
  <p>The last  should be recognized and added to <code>emoticon</code></p>