Apple IIe - Page 132

132 Apple lie Users Handbook
Configuration
expression 1 OR expression 2
expression 1 and expression 2 are Boolean expressions. If the
expression is numeric (non-zero), it xviii be evaluated to true. A
zero is treated as false. A truth table for OR is illustrated below.
x
y
XORY
true true true
true
false true
false true true
false
false false
In
both Applesoft and Integer BASIC, a true is represented by a 1
and false
by a 0.
10 A =3
20 B = 5
Example
30 IF (B < A) OR (B = 5) THEN 50
40 END
50 PRINT "EITHER BIS LESS THAN A"
60 PRINT "ORB IS EQUAL TO 5"
70 END
]RUN [Ret]
EITHER
BIS LESS THAN A
OR B IS EQUAL TO 5
In
the preceding example , Bis not less than A, but Bis equal to 5.
Therefore, the whole OR expression is true, and the program
branches to line 50.