Sharp MZ-800 - Page 49

(3) Relational expressions
Relational expressions are used to compare two values and ascribe a logical value of either true (— 1)
or false (0) to the expression according to the result of the comparison. The result is used to make
a decision regarding subsequent program flow, A relational expression can consist of constants, varia-
bles, arithmetic expressions, string connective expressions and relational operators.
The table below lists the relational operators.
joe Operate | Comparison Example
| Equal to X=Y
| < Less than X<Y
| > Greater than | X>Y
| <=, =< | Less than or equal to | X<=Y, X=<Y
>=, => | Greater than or equal to| X>=, X=>Y
= >< | Not equal to | x<>Y, X><Y
Note:
The relational values of character data are based on the characters’ ASCII codes.
(4) Logical expressions
A logical expression expresses the Boolean sum or product of true or false values (—1 or 0)
given by relational expressions. A logical expression is formed of logical values, relational ex-
pressions and logical operators. The following table lists the logical operators.
Operator Meaning | Example |
NOT Logical negation | NOT X |
AND Logical product XWAND Y
OR Logical sum X.OR Y
XOR__| Exclusive OR [XcxoryY |
Note:
Spaces indicated by —. must be included.
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