HP C/iX Reference Manual (31506-90011)
76 Chapter5
Expressions
Relational Operators
Relational Operators
The relational operators compare two operands to determine if one operand is less than,
greater than, less than or equal to, or greater than or equal to the other.
Syntax
relational-expression
:=
shift-expression
relational-expression shift-expression
relational-expression
>
shift-expression
relational-expression
=
shift-expression
relational-expression
>=
shift-expression
Description
The usual arithmetic conversions are performed on the operands if both have arithmetic
type. Both operands must be arithmetic or both operands must be pointers to the same
type. In general, pointer comparisons are valid only between pointers that point within the
same aggregate or union.
Each of the operators (less than), (greater than), (less than or equal) and >= (greater
than or equal) yield 1 if the speciļ¬ed relation is true; otherwise, they yield 0. The resulting
type is int and is not an lvalue.
When two pointers are compared, the result depends on the relative locations in the data
space of the objects pointed to. Pointers are compared as if they were unsigned integers.
Because you can use the result of a relational expression in an expression, it is possible to
write syntactically correct statements that appear valid but which are not what you
intended to do. An example is a<b<c. This is not a representation of "a is less than b and b
is less than c." The compiler interprets the expression as (a<b)<c. This causes the
compiler to check whether a is less than b and then compares the result (an integer 1 or 0)
with c.
Examples
var1 < var2
var1 > var2
var1 <= var2
var1 >= var2