Quick start manual

Syntactic elements 4-5
Fundamental syntactic elements
Labels
A label is a standard Delphi language identifier with the exception that, unlike other
identifiers, labels can start with a digit. Numeric labels can include no more than ten
digits—that is, a numeral between 0 and 9999999999.
Labels are used in goto statements. For more information about goto statements and
labels, see “Goto statements” on page 4-20.
Character strings
A character string, also called a string literal or string constant, consists of a quoted
string, a control string, or a combination of quoted and control strings. Separators can
occur only within quoted strings.
A quoted string is a sequence of up to 255 characters from the extended ASCII
character set, written on one line and enclosed by apostrophes. A quoted string with
nothing between the apostrophes is a null string. Two sequential apostrophes in a
quoted string denote a single character, namely an apostrophe. For example,
'BORLAND' { BORLAND }
'You''ll see' { You'll see }
'''' { ' }
'' { null string }
' ' { a space }
A control string is a sequence of one or more control characters, each of which consists
of the # symbol followed by an unsigned integer constant from 0 to 255 (decimal or
hexadecimal) and denotes the corresponding ASCII character. The control string
#89#111#117
is equivalent to the quoted string
'You'
You can combine quoted strings with control strings to form larger character strings.
For example, you could use
'Line 1'#13#10'Line 2'
to put a carriage-return–line-feed between “Line 1” and “Line 2”. However, you
cannot concatenate two quoted strings in this way, since a pair of sequential
apostrophes is interpreted as a single character. (To concatenate quoted strings, use
the + operator described in “String operators” on page 4-9, or simply combine them
into a single quoted string.)
A character string’s length is the number of characters in the string. A character string
of any length is compatible with any string type and with the PChar type. A character
string of length 1 is compatible with any character type, and, when extended syntax
is enabled ({$X+}), a character string of length n ≥ 1 is compatible with zero-based
arrays and packed arrays of n characters. For more information about string types,
see Chapter 5, “Data types, variables, and constants”.