title: How String.charAt(int i) is implemented in Java?
body: <p>If I want to check every char in a String using <code>String.charAt(int i)</code>, would it count from start every time or it is converted to an array automatically and get the <code>charAt</code> index directly?</p>
  
  <p>Would it be more efficient if I create a char array by <code>String.toCharArray()</code> and then go through the array by index?</p>
  
  <p>Can I check this up in JavaDoc? Where?</p>