C Data type

ANSI C provides three types of data-types.

1. Primary Data Types
2. Derived Data Type
3. User Defined Data Types

 

Primitive data types:

Void	It holds no value and generally used with function.
Int	It is used to denote an integer type.
Char	It is used to denote a character type.
float, double	It is used to denote a floating point type.
int *, float *, char *	It is used to denote a pointer type.

Primitive data types are used to hold the maximum value. Every C compiler supports five primary data types:

Example:

int a=90;  //  valid
a=90;  //   invalid

Derived  Data Type: Derived data types are derived from fundamental data type.  Variable of derived data type allows us to store the value of the same time in one variable. C supports three derived data types:

Arrays	Arrays are sequences of data items that have homogeneous values and adjacent memory locations to store values.
References	Function pointers allow referencing functions with a particular signature.
Pointers	It is used to access memory and deal with their addresses.

Example:

int mark[5]={10, 20, 30, 40};
int *a;

User Defined Data Types: The user-defined data type is used to store multiple values. There are various user-defined data types are given below in the table.

Data Types	Description
Structure	The structure is a package of variables under a single name. The “struct” keyword is used to define a structure.
Union	It is used to store the various data types in the same memory location.
Enum	It consists of integral constants and each of them is assigned with a specific name. It is defined as “enum” keyword.

Example:

struct student
{
int id;
char name[10];
float mob;
};

C Data Type with size

Let us consider an example to find the memory size of data type:

 
#include 
int main()
{
int a;
char b;
float c;
double d;
printf("Storage size for int data type:%d \n",sizeof(a));
printf("Storage size for char data type:%d \n",sizeof(b));
printf("Storage size for float data type:%d \n",sizeof(c));
printf("Storage size for double data type:%d\n",sizeof(d));
return 0;
}

Data Types	Memory Size	Range
char	1 byte	?128 to 127
signed char	1 byte	?128 to 127
unsigned char	1 byte	0 to 255
short	2 byte	?32,768 to 32,767
signed short	2 byte	?32,768 to 32,767
unsigned short	2 byte	0 to 65,535
int	2 byte	?32,768 to 32,767
signed int	2 byte	?32,768 to 32,767
unsigned int	2 byte	0 to 65,535
short int	2 byte	?32,768 to 32,767
signed short int	2 byte	?32,768 to 32,767
unsigned short int	2 byte	0 to 65,535
long int	4 byte	-2,147,483,648 to 2,147,483,647
signed long int	4 byte	-2,147,483,648 to 2,147,483,647
unsigned long int	4 byte	0 to 4,294,967,295
float	4 byte	1E–37 to 1E+37 with six digits of precision
double	8 byte	1E–37 to 1E+37 with ten digits of precision
long double	10 byte	1E–37 to 1E+37 with ten digits of precision