Campbell CR800 Series, Руководство оператора

Страница: 162 / 598

Section 7. Installation
162
Boolean from FLOAT or LONG
When a
FLOAT
or
LONG
is converted to a
Boolean
as shown in CRBasic
example Conversion of FLOAT / LONG to Boolean
(p. 162),
zero becomes false ( 0 )
and non-zero becomes true ( -1 ).
Conversion of FLOAT / LONG to Boolean
'This program example demonstrates conversion of Float and Long data types to Boolean
'data type.
Public Fa As Float
Public Fb As Float
Public L As Long
Public Ba As Boolean
Public Bb As Boolean
Public Bc As Boolean
BeginProg
Fa = 0
Fb = 0.125
L = 126
Ba = Fa
'This will set Ba = False (0)
Bb = Fb 'This will Set Bb = True (-1)
Bc = L 'This will Set Bc = True (-1)
EndProg
FLOAT from LONG or Boolean
When a LONG or Boolean is converted to FLOAT , the integer value is loaded
into the FLOAT . Booleans are converted to -1 or 0 . LONG integers greater
than 24 bits (16,777,215; the size of the mantissa for a FLOAT ) will lose
resolution when converted to FLOAT .
LONG from FLOAT or Boolean
When converted to Long, Boolean is converted to -1 or 0 . When a FLOAT is
converted to a LONG , it is truncated. This conversion is the same as the INT
function (Arithmetic Functions). The conversion is to an integer equal to or less
than the value of the float; for example,
4.6
becomes
4
and –
4.6
becomes –
5
).
If a FLOAT is greater than the largest allowable LONG (+2,147,483,647), the
integer is set to the maximum. If a FLOAT is less than the smallest allowable
LONG (–2,147,483,648), the integer is set to the minimum.
Integers in Expressions
LONG s are evaluated in expressions as integers when possible. CRBasic example
Evaluation of Integers
(p. 162)
illustrates evaluation of integers as LONG s and
FLOAT
s.