HP C A.06.05 Reference Manual

Program Organization
Declarations
Chapter 218
void
The void data type has three important purposes:
• To indicate that a function does not return a value
• To declare a function that takes no arguments
• To allow you to create generic pointers.
To indicate that a function does not return a value, you can write a function definition such as:
void func(int a, int b)
{
. . .
}
This indicates that the function func() does not return a value. Likewise, on the calling side,
you declare func() as:
extern void func(int, int);
volatile
Specifies that the value of a variable might change in ways that the compiler cannot predict. If
volatile is used, the compiler will not perform certain optimizations on that variable.
while
See “while” on page 182.
Declarations
In general, a variable declaration has the following format:
[ storage_class_specifier ] [ data_type ] variable_name [= initial_value ];
where:
storage_class_specifier is an optional keyword.
data_type is one of the data types described in Chapter 3, “Data
Types and Declarations.”
variable_name is a legal identifier.