Data Types in C

In C programming language, data types are used for declaring variables and functions.The type of a variable determines how much space it takes in storage and how the bit pattern stored is interpreted.

C Programming

The data types in C can be classified as follows:
1. Basic Types:
They are arithmetic types and are of the two types: (a) integer types and (b) floating-point types.
2.Enumerated types:
They are also arithmetic types and they are used to define variables that can only be assigned certain discrete integer values throughout the program.
3.The type void:
The type specifier void indicates the no value .
4.Derived types:
They include (a) Pointer types, (b) Array types, (c) Structure types, (d) Union types and (e) Function types.
The array types and structure types are the aggregate data types. The data type of a function specifies the type of function's return value.The basic data types are in the following section

Integer Types:

Following table shows you details about standard integer types with its storage sizes and value ranges:

Type Storage size Value range
char   1 byte -128 to 127 or 0 to 255
unsigned char 1 byte 0 to 255
signed char    1 byte - 128 to 127
int 2 or 4 byte -32,768 to 32,767 or -2,147,483,648 to 2,147,483,648
unsigned int   2 or 4 bytes 0 to 65,535 or 0 to 4,294,967,296
short    2 bytes 32,768 to 32,765
unsigned short 2 bytes 0 to 65,536
long 4 bytes -2,147,483,648 to 2,147,483,646
unsigned long 4 bytes 0 to 4,294,967,294

To get the size of the a variable on a particular platform, we can use the sizeof function. The sizeof(type) yields the storage size of the object or type in bytes.Example

#include <stdio.h>
#include <limits.h>

int main()
{
printf("Storage size for int : %d \n", sizeof(int));

return 0;
}
result on Linux:

Storage size for int : 4

Floating-Point Types:

Following table shoes you details about standard floating-point types with sizes , ranges and their precision:

Type Storagesize 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
The header file float.h defines macros that allow you to use these values and other details about the binary representation of real numbers in your programs.

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

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;
}
After compilation , it produces the following result on Linux:

Storage size for float : 4
Minimum float positive value: 1.175493E-38
Maximum float positive value: 3.402823E+38
Precision value: 6

The void Type:

Following table shoes you details about the void type.
1.Function returns as void:
A function with no return value has the return type as void.
For example void exit (int status);
2.Function arguments as void:
A function with no parameter . For example, int example(void);
3.Pointers to void:
A pointer of type void represents the address , but not its type.