title: Determine number of possible combinations of String in Java
body: <p>I was able to figure out how to produce a random alphanumeric string after refreshing my Java Knowledge. Here is a my method:</p>
  
  <pre><code>private static final String ALPHA_NUMERIC_STRING = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  
   String idGenerator(int count){
          StringBuilder builder = new StringBuilder();
  
          while (count-- != 0) {
  
              int character = (int)(Math.random()*ALPHA_NUMERIC_STRING.length());
  
              builder.append(ALPHA_NUMERIC_STRING.charAt(character));
  
          }
  
          return builder.toString();
  }
  </code></pre>
  
  <p>However, I was wondering how many possible combinations of string can my <code>idGenerator</code> method produce? Is there a built in method, class or a possible algorithm to determine this? Thanks!</p>