Vector Basic Interpreter Basic 80 Reference Manual - page 24
1.S.4
Functional Operators
A function is used in an expression to call a
predetermined
operation
that
is to be performed on an operand.
BASIC-SO
has "intrinsic" functions that reside in the system, such as
SQR
(square
root)
or
SIN,
(sine).
All
of
BASIC-SO's
intrinsic functions are described in Chapter 3.
BASIC-SO also
allows
"user
defined"
functions
that
are
written by the programmer.
See OEF FN, Section 2.11.
1.S.5
String Operations
Strings may be concatenated using
+.
For example:
10 A$-"FILE"
: B$."NAME"
20 PRINT A$
+ B$
30 PRINT "NEW "
+
A$
+
B$
RON
FILENAME
NEW FILENAME
Strings may be compared using the same relational
operators
that are used with numbers:
String comparisons are made by taking
one
character
at
a
time from each string and comparing the ASCII codes.
If all
the ASCII codes are the same, the strings are equal.
If the
ASCII codes
differ,
the
lower
code
number precedes· the
higher.
If, during string comparison, the end of one string
is reached,
the
shorter
string
is
said
to be
smaller.
Leading and trailing blanks are significant.
Examples:
"AA"
<
"AB"
"FILENAME" • "FILENAME"
"X,"
>
"X."
"CL "
> "CL"
"kg"
>
"KG"
" SMYTH"
<
"SMYTHE·
t
B$
< "9/12/7S"
where B$ • "S/12/7S"
Thus, string comparisons can be used to test
string
values
or
to
alphabetize
strings.
All string constants used in
comparison expressions must be enclosed in quotation marks.