HOW CHARACTERS ARE INTERNALLY REPRESENTED
Internally, most computers store characters according to the ASCII format. ASCII stands for American Standard Code for Information Interchange. Characters are stored according to a numbered sequence, whereby A has a value of 64 decimal, B a value of 65 etc. Several functions which manipulate characters follow.

• CHR
  The chr or character position function returns the character associated with the ASCII value being asked, eg,

  
        chr( 65 )   will return the character   A
  

• ORD
  The ord or ordinal function returns the ASCII value of a requested character. In essence, it works backwards to the chr function. Ordinal data types are those which have a predefined, known set of values.
  Each value which follows in the set is one greater than the previous. Characters and integers are thus ordinal data types.

  
       ord( 'C' )   will return the value   67
  

• SUCC
  The successor function determines the next value or symbol in the set, thus

  
       succ( 'd' )  will return  e
  

• PRED
  The predecessor function determines the previous value or symbol in the set, thus

  
       pred( 'd' )  will return  c