Radio Shack TRS-80 model III Owner's Manual page 108

DISK BASIC
Examples
DEF FNR(AtB)
=
A
+
INT((B
-
(A
-
1))
*
RND<0>>
This statement
defines function
fnr which
returns a
random number between
integers
A
and B.
The
values for
A
and
B
are
passed
when
the function
is
"called,"
i.e.,
used
in a
statement
like:
Y
=
FNR(R1
*
R2)
If
ri
and R2
have been assigned
the
values
2 and
8, this line
would
assign a
random number between
2
and
8 to
y.
DEF FNL$(K)
=
STRING*(Xf
"-")
Defines function
fnl$
which
returns a string
of
hyphens,
x
characters long.
The
value
for
x
is
passed
when
the function
is
called:
PRINT FNL$<3)
This line prints a string
of
30 hyphens.
Here's
an
example showing def fn used
for a
complex computation
—
in
double-precision.
DEF
FNX#(A#*
B#)
=
<A#
-
B»)
*
(A«
-
B«)
Defines function
fnx#
which
returns the
double-precision value of
the
square of
the difference
between
a#
and b#.
The
values for
a#
and
b#
are
passed
when
the
function
is
called:
S#
=
FNX*(A#> B«)
We
assume
that
values for
a#
and
b#
were
assigned elsewhere
in
the
program.
Sample Program
71(3
DEF FNV(T>
=
(1S87
+
SQR(273
+
T))/1G
#
52
720 INPUT "AIR
TEMPERATURE
IN
DEGREES CELSIUS";
T
730 PRINT "THE SPEED OF
SOUND
IN
AIR OF"
T
"DEGREES
CELSIUS
IS"
FNV<T)
"FEET PER SECOND*"
107