title: java: what's the most efficient way to remove all blank space from a StringBuilder
body: <p>I implement it by the following code, but I don't know whether there's a more efficient way to remove all blank spaces from a StringBuilder</p>
  
  <pre><code>private static StringBuilder removeBlankSpace(StringBuilder sb){
      for(int i=0;i&lt;sb.length();++i){
          if(Character.isWhitespace(sb.charAt(i))){
              sb.deleteCharAt(i);
                              i--;
          }
      }
      return sb;
  }
  </code></pre>