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 specified 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.
