Data Types

As the name suggests, data-type specifies the type of the data present in the variable. Variables must be declared with a data-type.

There are four different types of Data types in C.

Types	Data-type
Basic	int, char, float, double
Derived	array, pointer, structure, union
Enumeration	enum
Void	void

1. Basic data types

Basic data types are generally arithmetic types which are based on integer and float data types. They support both signed and unsigned values. Below are some of the oftenly used data types

Data type	Description	Range	Memory Size	Format specifier
int	used to store whole numbers	-32,768 to 32,767	2 bytes	%d
short int	used to store whole numbers	-32,768 to 32,767	2 bytes	%hd
long int	used to store whole numbers	-2,147,483,648 to 2,147,483,647	4 bytes	%li
float	used to store fractional numbers	6 to 7 decimal digits	4 bytes	%f
double	used to store fractional numbers	15 decimal digits	8 bytes	%lf
char	used to store a single character	one character	1 bytes	%c

Examples

#include <stdio.h>
#include <float.h>

int main()
{
int x = 90;
int y = sizeof(x);
printf("size of x is: %d " , y);

float f = 3.14;
printf("\nsize of float is: %d " , sizeof(f));

double d = 2.25507e-308;
printf("\nsize of double is: %d " , sizeof(d));

char c = 'a';
printf("\nsize of char is: %d " , sizeof(c));
}

Check result here

2. Derived Data types

Derived Data types are the ones which are derived from fundamental data types. Arrays, Pointers, Structures, etc. are examples of derived data types. Let's learn more about them in next chapters.

3. Enumeration Data types

Enumeration Data type is a user-defined data type in C. enum keyword is used to declare a new enumeration types in C.

Syntax

enum name{constant1, constant2, constant3, ....... };

Example

#include<stdio.h> 
  
enum month{January, February, March, April, May, June, July, August, September, October, November, December};
  
int main() 
{ 
    enum month name; 
    name = June; 
    printf("%d",name); 
    return 0; 
} 

Check result here

4. Void Data types

Void specifies that there is no return value. Generally void is used in the below situations.

• If the funtion has return type mentioned as Void, then it specifies that the function returns no value.
• A function with out any parameters can accept void. For example., char greetings(void)
• A pointer with type specified as void represents the address of an object but not it's type. Let's learn more about pointers in next chapters.