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CHAPTER 1. PDF
6
Comments
There is a possibility to use comment in PDF, using the % character. Everything that follows
after the % character is comment. The comment is ended by an end of line. PDF ignores
comments, treating them as if they were single white-space characters.
1.3.2 Objects
PDF supports 8 types of objects:
Booleans are true or false and often used in if/else structures.
Numeric objects are integers or real numbers.
integer value examples: 10 -98 0
real number value examples: 33.2 -98.6 0.0
Strings There are two types: “literal” strings and “hexadecimal” strings
Literal strings are a number of characters enclosed in parentheses. Any character
may appear in a string except unbalanced parentheses and the backslash, which is
used for escape sequences (\t = tab etc).
Examples: (This is a string), (Strings may contain balanced parentheses ( ) and
special characters (*!&}ˆ% and so on).)
If a string is too long to be easily placed on a single line, it may be split across
multiple lines by using the backslash character at the end of a line to indicate
that the string continues on the following line. If the backslash is followed by the
end-of-line marker, they are not considered part of the string.
Example: (These \
two strings \
are the same.)
(These two strings are the same.)
Hexadecimal strings are written as a sequence of hexadecimal digits (0-9 and either
A-F or a-f) enclosed within angle brackets ( and )
Example: 35A35F3B
Names are very small symbols uniquely defined by a sequence of characters. They are often
usedwith variable strings,such as font names whichare not known whenthe programme
is written. Names start with an /, example: /Name1.
Arrays are a one-dimensional collection of objects arranged sequentially. They may be any
combination of numbers, strings, dictionaries, or any other objects, including other
