title: performance of string.tolowercase on a lower case string
body: <p>I want to know the implications of the <code>toLowerCase</code> on a String. The string here can vary in length up to 50 chars and can be a lower case also. </p>
  
  <p>In our case, We need to check for the string which in entered by user and then saving that input, in lower case, in database and its to be checked on a large volume.</p>
  
  <p>So should I check for the case mismatch first and then apply the <code>String.toLowerCase</code> OR directly always apply the <code>String.toLowerCase()</code> on every string including lower case strings.</p>
  
  <p>Is there any better way to handle such type of situations keeping performance in mind?</p>
  
  <p>Thanks in advance.</p>