Data_Types

 The data type of an object must be specified in its declaration.
 The fundamental data types are the scalar types:

 short int           16-bit signed integer
 signed short int    16-bit signed integer
 unsigned short int  16-bit unsigned integer
 int                 32-bit signed integer
 signed int          32-bit signed integer
 unsigned int        32-bit unsigned integer
 long int            32-bit signed integer
 signed long int     32-bit signed integer
 unsigned long int   32-bit unsigned integer
 long long int       64-bit signed integer
 signed long long int     64-bit signed integer
 unsigned long long int   64-bit unsigned integer
 char                8-bit signed integer
 signed char         8-bit signed integer
 unsigned char       8-bit unsigned integer
 wchar_t             Long character (32-bit unsigned integer)
 float               32-bit (single-precision) floating-point number
 double              64-bit (double-precision) floating-point number
 long double         128-bit (double-precision) floating-point
                     number
 long float          Interchangeable with double, but usage is
                     obsolete
 _Bool               An unsigned int that has the value 0 or 1
 _Imaginary          A C99-specified data type.  In VSI C, use of
                     the _Imaginary keyword produces a warning,
                     which is resolved by treating it as an ordinary
                     identifier.
 _Complex            C99-specified data type available in all three
                     precisions:  float _Complex, double _Complex,
                     or long double _Complex.  A complex type has
                     the same representation and alignment
                     requirements as an array type containing
                     exactly two elements of the corresponding real
                     type; the first element is equal to the real
                     part, and the second element to the imaginary
                     part, of the complex number.

                     Note:  This complex data type is similar to the
                     Fortran type, and has an associated header
                     file, <complex.h>.  Although the fundamental
                     complex data types are implemented in the
                     compiler, the run-time support will not be
                     available until an OpenVMS Alpha release
                     following Version 7.3.

 The signed keyword is the default.  Declaring an object with int,
 for example, is equivalent to declaring it with signed int.
 However, char declarations should be explicitly declared, as the
 compiler offers command-line options to change the default.  If in
 doubt, use signed char over char because signed char is more
 portable.

 Strings are arrays of characters terminated by the null character
 (\0).

 Also, view the contents of the <ints.h> header file for definitions
 of platform-specific integer types.

Additional information available:

Array           enum            Pointer         Structure       typedef
Union           Void