Commodore VIC-20 User Manual page 82

68
The VIC 20 User Guide
Operators
The BASIC statement
lee ?l0. 2+4."
tells the VIC to add 10.2 and 4.7, and then display the sum. The statement
250 C-Fl+B
tells the VIC to add the two floating point numbers represented by the
variable names A and B, and to assign the sum to the floating point number
represented by the variable name C.
The plus sign specifies addition. The plus sign is referred to as an
operator. It
is an arithmetic operator, since addition is an arithmetic opera-
tion. There are two other types of operators: relational operators and
Boolean operators. These take a little more explanation, since they reflect
conditions and decisions, rather than arithmetic.
Table 3-2 summarizes the BASIC operators. We will examine each
group of operators in turn, beginning with arithmetic operators.
TABLE
3·2.
Operators
Precedence
Operator
Meaning
High
9
()
Parentheses denote order of evaluation
8 I Exponentiation
.!:!
~
7
-
Unary minus
~
=
E'ii
6
•
Multiplication
.c: ..
6 /
Division
... a.
... =-
.<0
5
+ Addition
5
-
Subtraction
4
=
Equal
-
'"
4
<>
Not equal
"
. .
=
=
= ...
4
<
Less than
i
f
4
>
Greater than
-as!.
=:0
4
<= or=<
Less than or equal
4
>= or=>
Greater than. or equal
'"
3
N01 Logical complement
= ..
" =
2 AND Logical AND
a.'"
-
".
= ..
I OR Logical OR
=
a.
==-
Low
0