DATA TYPES IN C++

C++ supports three kinds of object types:

Fundamental types are built into the language (such as int, float, or double). Instances of these fundamental types are often called “variables” .

Derived types are new types derived from built-in types. 

Class types are new types created by combining existing types.
Fundamental Types of the C++ Language

Category	Type	Contents
Integral	char	Type char is an integral type that usually contains members of the execution character set — in Microsoft C++, this is ASCII.
		The C++ compiler treats variables of type char, signed char, and unsigned char as having different types. Variables of type char are promoted to int as if they are type signed char by default, unless the /J compilation option is used. In this case they are treated as type unsigned char and are promoted to int without sign extension.
	short	Type short int (or simply short) is an integral type that is larger than or equal to the size of type char, and shorter than or equal to the size of type int.
		Objects of type short can be declared as signed short or unsigned short. Signed short is a synonym for short.
	int	Type int is an integral type that is larger than or equal to the size of type short int, and shorter than or equal to the size of type long.
		Objects of type int can be declared as signed int or unsigned int. Signed int is a synonym for int.
	Long	Type long (or long int) is an integral type that is larger than or equal to the size of type int.
		Objects of type long can be declared as signed long or unsigned long. Signed long is a synonym for long.
Floating	float	Type float is the smallest floating type.
	double	Type double is a floating type that is larger than or equal to type float, but shorter than or equal to the size of type long double.
	long double	Type long double is a floating type that is equal to type double.

Sizes of Fundamental Types

Type	Size
char, unsigned char, signed char	1 byte
short, unsigned short	2 bytes
int, unsigned int	4 bytes
long, unsigned long	4 bytes
float	4 bytes
double	8 bytes
long double	8 bytes