OR _ _ _ _ _ _ _ _ _ _ _ _ operator
The or binary logical operator returns true if either one or both of its arguments is true.
<logical expression> or <logical expression>
<logical expression> must evaluate to true or nil.
a := 10; A := 10 if a<0 or a>140 then write "not a valid human age" else write "age = ",a; age = 10 a := 200; A := 200 if a < 0 or a > 140 then write "not a valid human age"; not a valid human age
The or operator is left associative: x or y or z is equivalent to (x or y) or z.
Logical operators can only be used in conditional expressions, such as
if...then...else and while...do. or evaluates its arguments in order and quits, returning true, on finding the first true statement.