strings                  Character Strings                               [TP]

    Standard Pascal does not define a standard string data type. It does,
    however, recognize string literals, such as in the statement:

         Writeln('Hello, world!');

    A string literal is a sequence of characters between single quotes.
    One character between single quotes is considered (by Standard Pascal)
    to be a character literal.

    Standard Pascal allows the assignment of string literals to variables
    which are declared as being PACKED ARRAY[1..N] OF Char, where N is
    some constant value. However, the strings assigned to those variables
    must be exactly N characters long. There is no such thing as a string
    of length 0.

    Turbo Pascal predefines a standard STRING data type which allows
    greater flexibility than does Standard Pascal. String variables are
    declared as follows:

         var
           Name      : string[MaxLen];

    where MaxLen is some constant value specifying the maximum length of
    any string assigned to Name. MaxLen must be in the range 1..255. You
    can then assign strings of any length from 0 up to and including
    MaxLen. A string literal is any number of characters between single
    quotes; the null string (length=0) is simply two single quotes with no
    characters between them.

    Strings are represented in Turbo Pascal as arrays of Char. A variable
    declared as being STRING[MaxLen] is really ARRAY[0..MaxLen] OF Char,
    with  one byte per character. Location 0 is used to store the current
    (as  opposed to the maximum) length of the string. You can directly
    reference any character in the string by subscripting as you would an
    array. For example, if you assign 'Norton' to Name, then Name[4] =
    't'.

    Turbo Pascal defines a set of procedures and functions for string
    manipulation. It also uses '+' as a concatenation operator and allows
    the use of all the relational operators.

  -------------------------------- Example ---------------------------------

           var
             Iota  : string[2];
             Able  : string[60];
             Fred  : string[255];

           begin
             Iota := 'Hi';
             Able := 'Hello, there.';
             Fred := 'Well, aren''t you going to do anything?';
           end.