Data types in c refer to an extensive system used for declaring variables or functions of different types. The type of a variable determines how much space it occupies in storage and how the bit pattern stored is interpreted.

The types in C can be classified as follows −

To get the exact size of a type or a variable on a particular platform, you can use the sizeof operator. The expressions sizeof(type) yields the storage size of the object or type in bytes. Given below is an example to get the size of various type on a machine using different constant defined in limits.h header file −

#include

#include

#include

#include

int main(int argc, char** argv) {

    printf("CHAR_BIT    :   %d\n", CHAR_BIT);

    printf("CHAR_MAX    :   %d\n", CHAR_MAX);

    printf("CHAR_MIN    :   %d\n", CHAR_MIN);

    printf("INT_MAX     :   %d\n", INT_MAX);

    printf("INT_MIN     :   %d\n", INT_MIN);

    printf("LONG_MAX    :   %ld\n", (long) LONG_MAX);

    printf("LONG_MIN    :   %ld\n", (long) LONG_MIN);

    printf("SCHAR_MAX   :   %d\n", SCHAR_MAX);

    printf("SCHAR_MIN   :   %d\n", SCHAR_MIN);

    printf("SHRT_MAX    :   %d\n", SHRT_MAX);

    printf("SHRT_MIN    :   %d\n", SHRT_MIN);

    printf("UCHAR_MAX   :   %d\n", UCHAR_MAX);

    printf("UINT_MAX    :   %u\n", (unsigned int) UINT_MAX);

    printf("ULONG_MAX   :   %lu\n", (unsigned long) ULONG_MAX);

    printf("USHRT_MAX   :   %d\n", (unsigned short) USHRT_MAX);

    return 0;

}

When you compile and execute the above program, it produces the following result on Linux −

CHAR_BIT    :   8

CHAR_MAX    :   127

CHAR_MIN    :   -128

INT_MAX     :   2147483647

INT_MIN     :   -2147483648

LONG_MAX    :   9223372036854775807

LONG_MIN    :   -9223372036854775808

SCHAR_MAX   :   127

SCHAR_MIN   :   -128

SHRT_MAX    :   32767

SHRT_MIN    :   -32768

UCHAR_MAX   :   255

UINT_MAX    :   4294967295

ULONG_MAX   :   18446744073709551615

USHRT_MAX   :   65535

Floating-Point Types

The following table provide the details of standard floating-point types with storage sizes and value ranges and their precision −

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. The following example prints the storage space taken by a float type and its range values −

#include

#include

#include

#include

int main(int argc, char** argv) {

    printf("Storage size for float : %d \n", sizeof(float));

    printf("FLT_MAX     :   %g\n", (float) FLT_MAX);

    printf("FLT_MIN     :   %g\n", (float) FLT_MIN);

    printf("-FLT_MAX    :   %g\n", (float) -FLT_MAX);

    printf("-FLT_MIN    :   %g\n", (float) -FLT_MIN);

    printf("DBL_MAX     :   %g\n", (double) DBL_MAX);

    printf("DBL_MIN     :   %g\n", (double) DBL_MIN);

    printf("-DBL_MAX     :  %g\n", (double) -DBL_MAX);

    printf("Precision value: %d\n", FLT_DIG );

    return 0;

}

When you compile and execute the above program, it produces the following result on Linux −

Storage size for float : 4 

FLT_MAX      :   3.40282e+38

FLT_MIN      :   1.17549e-38

-FLT_MAX     :   -3.40282e+38

-FLT_MIN     :   -1.17549e-38

DBL_MAX      :   1.79769e+308

DBL_MIN      :   2.22507e-308

-DBL_MAX     :  -1.79769e+308

Precision value: 6

The void Type

The void type specifies that no value is available. It is used in three kinds of situations −