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33
True BASIC Language System
Example: The following program:
LIBRARY "StrLib.trc"
DECLARE DEF ShortDate$
PRINT ShortDate$("19971015")
END
produces the following output:
15 Oct 97
Exceptions: 1 Bad date given to ShortDate$: 00000000
See also: DATE$, DATE, SHORTDATE$, WEEKDAY$, WEEKDAY, TODAY$, TIME, TIME$,
NICETIME$, NOW$
SUPERVAL Subroutine
Library:
Syntax:
strarrarg::
Usage:
Summary:
Details:
STRLIB.TRC
CALL SUPERVAL (strarrarg, strex, numvar)
strarr
strarr bowlegs
CALL SUPERVAL (table$(), expression$, result)
Evaluates the expression represented by the contents of expression$ and returns the
resulting value in result.
The SUPERVAL subroutine evaluates the numeric expression represented by the value of
expression$ and returns the resulting value in result.
The value of expression$ must represent a numeric expression which is valid under the
rules of True BASIC. This expression may contain both numeric constants and variables.
You can use expressions like “a = 2” or “length, width, height = 1” to create variables and set
their values.
Like the numeric constants, the variables used in expression$ must follow True BASIC’s
rules for the formation of variable names. These variables are not connected with the variables
used in your program code; they form their own variable pool which is created and used
exclusively by the SUPERVAL subroutine.
The SUPERVAL subroutine uses the table$ array to manage this pool of variables. You
don’t need to worry about maintaining the table$ array; just pass any one-dimensional
array as table$, and the SUPERVAL subroutine will do the rest. However, since the
table$ array is used to store the variable pool, you should be sure to pass the same table$
array to each invocation of the SUPERVAL subroutine which you would like to have access
to the variables in that pool.
The value of expression$ may incorporate any of the following operators:
Operators Available to SUPERVAL
+ - * / ^ ( )
In addition, the value of expression$ may incorporate any of the following numeric functions:
Functions Available to SUPERVAL
SIN COS TAN ATN SQR
SINH COSH TANH ASIN ACOS
SEC CSC COT MAXNUM EPS
PI SGN ABS RAD DEG
LOG LOG2 LOG10 EXP RND
INT ROUND IP FP CEIL
DATE
TIME
Note that numeric functions requiring two arguments, including the two-argument form of
the ROUND function, are not available for use in the value of expression$.