Data Types in C Programming Language

Rumman Ansari   Software Engineer   2022-12-27   22063 Share
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A datatype is a special keyword used to allocate sufficient memory space for the data, in other words, Data type is used for representing the data in main memory (RAM) of the computer. Data types represent the different values to be stored in the variable. Every data type has a range of values. The compiler allocates memory space for each variable or constant according to its data type.

Each variable in C has an associated data type. Each data type requires different amounts of memory and has some specific operations which can be performed over it. Let us briefly describe them one by one:

Datatypes in C Programming

Data types in C

Primary data types

  1. Integer Types
  2. Floating-point Types
  3. Character Types

Enumerated types

  1. enum

Derived data types

  1. Arrays
  2. Pointer
  3. Structure
  4. Union

void

  1. void
Datatypes in c programming
Types Data Types
Basic Data Type int, char, float, double
Derived Data Type array, pointer, structure, union
Enumeration Data Type enum
Void Data Type void

Following are the examples of some very common data types used in C:

char: The most basic data type in C. It stores a single character and requires a single byte of memory in almost all compilers.
int: As the name suggests, an int variable is used to store an integer.
float: It is used to store decimal numbers (numbers with floating point value) with single precision.
double: It is used to store decimal numbers (numbers with floating point value) with double precision.

Primary data types

Integer Types

  • short
  • int
  • long

Floating-point Types

  • float
  • double

Character Types

  • char
Primary DataType in C

Primary Datatype or Basic Datatype

The memory size of basic data types may change according to 32 or 64 bit operating system. Let's see the basic data types. Its size is given according to 32 bit architecture.

Integer Type Datatype

Data Types Memory Size Range
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

Floating-points Datatypes

Type Storage size Value range Precision
float 4 byte 1.2E-38 to 3.4E+38 6 decimal places
double 8 byte 2.3E-308 to 1.7E+308 15 decimal places
long double 10 byte 3.4E-4932 to 1.1E+4932 19 decimal places

Character Types Datatypes

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

sizeof(DataType) Operator

To get the exact size of a type or a variable on a particular platform, you can use the sizeof operator.

To get the exact size of a type or a variable on a particular platform, you can use the sizeof operator. 

 // Run on 64 bit Machine

#include
int main() {

   printf("Storage size for int : %d \n", sizeof(int));
   
   return 0;
}
 
Storage size for int : 4
Press any key to continue . . .

Calculate Range

// Run on 64 bit Machine

#include 
#include 

int main() {

   printf("Storage size for float : %d \n", sizeof(float));
   printf("Minimum float positive value: %E\n", FLT_MIN );
   printf("Maximum float positive value: %E\n", FLT_MAX );
   printf("Precision value: %d\n", FLT_DIG );
   
   return 0;
 } 
 
Storage size for float : 4
Minimum float positive value: 1.175494E-038
Maximum float positive value: 3.402823E+038
Precision value: 6
Press any key to continue . . .
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