HP 3000 Manuals

HP Pascal/iX Reference Manual

String Literals 

String literals are sequences of characters, enclosed by single quote
marks, that may not be longer than a single line of source code.  String
literals may consist of any combination of the following:

   *   A sequence of ASCII characters enclosed in single quote marks.

   *   A sharp symbol (#) followed by a single character.

   *   A sharp symbol (#) followed by up to three digits that represent
       the ASCII value of a character.

A letter or symbol after a sharp symbol is equivalent to a control
character.  For example, #G or #g encodes CTRL-G, the bell character.
The compiler interprets the letter or symbol according to the expression
chr(ord(letter) MOD 32).  Therefore, the ordinal value of G is 71;
modulus 32 of 71 is 7; and the ASCII value of 7 is the bell.

In a string literal, if a number is used after a sharp symbol, it may
contain up to three digits, but must be in the range 0 through 255.  It
directly encodes any printing or nonprinting ASCII character.  For
example, the string literal #80#65#83#67#65# 76 is equivalent to the
string literal PASCAL.

Any ASCII character can appear between quote marks.  The sharp symbol #
is provided to enable better documentation of nonprinting characters.

A string literal may be type char, PAC, or string.  This is dependent on
the context in which it is used.  If a single quote is a character in a
string literal, it must appear twice, consecutively.

Two consecutive quote marks ('') are used to specify the null or empty
string literal.  Assigning this value to a string variable sets the
length of the variable to zero.  Assigning this value to a PAC variable
blank-fills the variable.

Syntax 

     String_literal:


            

Example 

     'Please don''t!'                    { Single quote character. }
     'A'
     ''                                  { Null string.            }
     #F
     #243#H
     #27'that was an ESC char, and so is this'#[
     'this string has five bells'#G#g#g#7#7' in it'

MPE/iX 5.0 Documentation