|=||= or EQ|
|<||< or LT|
|<=||<= or LE|
|<>||<> or NE|
|>||> or GT|
|>=||>= or GE|
The same letters are used for relational operators
in FORTRAN which also uses the same set of
logical operators — NOT, AND, OR and XOR — as
both the BASICs.
Most of the intrinsic functions in CBASIC are found
in MBASIC. The exceptions are as follows:
FLOAT — converts an implicitly declared integer to
its real number equivalent; if a real number is used
instead, it is converted to an integer and then
reconverted to its real equivalent.
INT% — this truncates a real number at the decimal
point and returns an integer result. If a real number
is to be converted, it is first converted to a real
number before truncation. Note that this is not the
same as the INT function which actually produces
a real result.
This highlights the fact that unnecessary conversions
and other operations will slow down a
program, and to minimize this, one should make
sure that any conversions are done using the right
type of number.
These are almost identical in both BASICs; the only
major difference is that, in addition to the letters
FN, up to 29 other alphanumeric characters may be
added in CBASIC.
Compared with MBASIC, CBASIC has several more
string functions; the following will give some idea
of the flexibility of this aspect of the dialect:
COMMAND$ — returns the CP/M command line
without the name of the CP/M program being
invoked. You probably won’t use this a lot.
MATCH(A$,B$,I$) — looks for string A$ starting at
the I%th character in string B$. If it is present, the
function returns the position in B$ of the first A$
character; if it is not present, the value 0 is
SADD(A$) — returns the starting address in
memory where CBASIC has stored A$.
UCASE(A$) — converts lower case letters to upper
case in string A$.
in addition to the normal IF … THEN … <ELSE>
statement, CBASIC has an amazing feature called
the Compound IF statement where many comparisons
can be made. A program which illustrates
this and the use of other CBASIC features may help
explain this very useful facility:
Another useful pair of statements found in both
BASICs, is WHILE/WEND; they are essentially a
variation of the FOR/NEXT statements and will
allow statements inserted between them to be
continually executed as long as the expression
following WHILE is logically true. As soon as it is
logically false, the sequence terminated and the
next statement after WEND is executed. This is
quite a nifty idea and additionally, Compound IF
statements can be included between them. The
following example illustrates the action of the