589: Mainline

When you wish to extract a particular character from a string, you use the charAt method, with the argument indicating the character that you wish to extract. A 0 argument indicates that you want the first character, because all string indexing is zero based, as is indexing for arrays and vectors:

  *-- Variable with a string assignment 
  | 
  |           *-- Method 
  |           | 
  |           |   *-- Index of character to be extracted 
  v           v   | 
---------- ------ v        
codeString.charAt(0)