C - <limits.h>
The C <limits.h> header file defines constants with the limits of fundamental integral types for the specific system and compiler implementation used. The limits for fundamental floating-point types are defined in <float.h>. The limits for width-specific integral types and other typedef types are defined in <stdint.h>.
C <limits.h> Macro Constants
The below mentioned macros are implementation-specific and defined with the #define directive. The table below shows the different macros in <limits.h> header and their minimal or maximal values in all implementations.
| Macros | Description | Value |
|---|---|---|
| CHAR_BIT | Number of bits in a char object (byte) | 8 or greater |
| SCHAR_MIN | Minimum value for an object of type signed char | (-27+1) or less |
| SCHAR_MAX | Maximum value for an object of type signed char | (27-1) or greater |
| UCHAR_MAX | Maximum value for an object of type unsigned char | (28-1) or greater |
| CHAR_MIN | Minimum value for an object of type char | either SCHAR_MIN or 0 |
| CHAR_MAX | Maximum value for an object of type char | either SCHAR_MAX or UCHAR_MAX |
| MB_LEN_MAX | Maximum number of bytes in a multi-byte character, for any locale | 1 or greater |
| SHRT_MIN | Minimum value for an object of type short int | (-215+1) or less |
| SHRT_MAX | Maximum value for an object of type short int | (215-1) or greater |
| USHRT_MAX | Maximum value for an object of type unsigned short int | (216-1) or greater |
| INT_MIN | Minimum value for an object of type int | (-215+1) or less |
| INT_MAX | Maximum value for an object of type int | (215-1) or greater |
| UINT_MAX | Maximum value for an object of type unsigned int | (216-1) or greater |
| LONG_MIN | Minimum value for an object of type long int | (-231+1) or less |
| LONG_MAX | Maximum value for an object of type long int | (231-1) or greater |
| ULONG_MAX | Maximum value for an object of type unsigned long int | (232-1) or greater |
| LLONG_MIN (C99) | Minimum value for an object of type long long int | (-263+1) or less |
| LLONG_MAX (C99) | Maximum value for an object of type long long int | (263-1) or greater |
| ULLONG_MAX (C99) | Maximum value for an object of type unsigned long long int | (264-1) or greater |
Example:
The example below describes the working of macros constant of C <limits.h> library.
#include <stdio.h>
#include <limits.h>
int main (){
printf("CHAR_BIT: %i\n", CHAR_BIT);
printf("CHAR_MIN: %i\n", CHAR_MIN);
printf("CHAR_MAX: %i\n", CHAR_MAX);
printf("SHRT_MIN: %i\n", SHRT_MIN);
printf("SHRT_MAX: %i\n", SHRT_MAX);
printf("LONG_MIN: %li\n", LONG_MIN);
printf("LONG_MAX: %li\n", LONG_MAX);
printf("LLONG_MIN: %lli\n", LLONG_MIN);
printf("LLONG_MAX: %lli\n", LLONG_MAX);
return 0;
}
The output of the above code is machine dependent. One of the possible output could be:
CHAR_BIT: 8 CHAR_MIN: -128 CHAR_MAX: 127 SHRT_MIN: -32768 SHRT_MAX: 32767 LONG_MIN: -9223372036854775808 LONG_MAX: 9223372036854775807 LLONG_MIN: -9223372036854775808 LLONG_MAX: 9223372036854775807
