<climits> library in C++

In this article, we will learn about climits library in C++. This library is used for managing and evaluating maximum and minimum values of several integer data-types.

• The climits is also known as limits.h library in C++.
• Sometimes it is very difficult for us to remember every limiting value of every type of data-type in C++. Hence we require a library which automatically tells us the limiting values of the datatypes.
• So instead of remembering all such values we can directly use such macros which makes the programming far easier.
• climits or limits.h defines sizes of integral types.
• NOTE: The actual value is system and library dependent, but the results gets reflected in the target system.
• Your Machine’s values depends upon whether it is 32 bit machine or 64 bit machine.

Macro Constants

The complete list of macro constants are:

• CHAR_MIN : -128
• CHAR_MAX : 127
• SHRT_MIN : -32768
• SHRT_MAX : 32767
• USHRT_MAX : 65535
• INT_MIN : -2147483648
• INT_MAX : 2147483647
• UINT_MAX : 4294967295
• LONG_MIN : -9223372036854775808
• LONG_MAX : 9223372036854775807
• ULONG_MAX : 18446744073709551615
• LLONG_MIN : -9223372036854775808
• LLONG_MAX : 9223372036854775807
• ULLONG_MAX: 18446744073709551615

1. CHAR_MIN :

CHAR_MIN: Minimum value for an object of type char (-127 or 0)

Minimum value for an object of type char
Value of CHAR_MIN is either -127 or less* or 0

2. CHAR_MAX :

CHAR_MAX: Maximum value for an object of type char (127 or 255)

Maximum value for an object of type char
Value of CHAR_MAX is either 127 or 255  or greater*

3. SHRT_MAX :

SHRT_MAX: Maximum value for an object of type short int (32767)

Maximum value for an object of type short int
Value of SHRT_MAX is 32767 or greater*

4. SHRT_MIN :

SHRT_MIN: Minimum value for an object of type short int (-32767)

Minimum value for an object of type short int
Value of SHRT_MIN is -32767 or less*

5. USHRT_MAX :

Maximum value for an object of type unsigned short int    
Value of USHRT_MAX is 65535 or greater*

6. INT_MIN :

Minimum value for an object of type int    
Value of INT_MIN is -32767 or less*

7. INT_MAX :

Maximum value for an object of type int    
Value of INT_MAX is 32767 or greater*

8. UINT_MAX :

Maximum value for an object of type unsigned int    
Value of UINT_MAX is 65535 or greater*

9. LONG_MIN :

Minimum value for an object of type long int    
Value of LONG_MIN is -2147483647 or less*

10. LONG_MAX :

Maximum value for an object of type long int    
Value of LONG_MAX is 2147483647 or greater*

11. ULONG_MAX :

Maximum value for an object of type unsigned long int    
Value of ULONG_MAX is 4294967295 or greater*

12. LLONG_MIN :

Minimum value for an object of type long long int    
Value of LLONG_MIN is -9223372036854775807 or less*

13. LLONG_MAX :

Maximum value for an object of type long long int    
Value of LLONG_MAX is 9223372036854775807 or greater*

14. ULLONG_MAX :

Maximum value for an object of type unsigned long long int    
Value of ULLONG_MAX is 18446744073709551615 or greater*

Implementation

• This program displays the respective values of macros on your machine :

#include <climits> 
#include <iostream>  
using namespace std;  
int main() 
{ 
    cout << "CHAR_MIN : " << CHAR_MIN << endl; 
    cout << "CHAR_MAX : " << CHAR_MAX << endl; 
    cout << "SHRT_MIN : " << SHRT_MIN << endl; 
    cout << "SHRT_MAX : " << SHRT_MAX << endl; 
    cout << "USHRT_MAX : " << USHRT_MAX << endl; 
    cout << "INT_MIN : " << INT_MIN << endl; 
    cout << "INT_MAX : " << INT_MAX << endl; 
    cout << "UINT_MAX : " << UINT_MAX << endl; 
    cout << "LONG_MIN : " << LONG_MIN << endl; 
    cout << "LONG_MAX : " << LONG_MAX << endl; 
    cout << "ULONG_MAX : " << ULONG_MAX << endl; 
    cout << "LLONG_MIN : " << LLONG_MIN << endl; 
    cout << "LLONG_MAX : " << LLONG_MAX << endl; 
    cout << "ULLONG_MAX : " << ULLONG_MAX << endl; 
    return 0; 
}

OUTPUT :

CHAR_MIN : -128
CHAR_MAX : 127
SHRT_MIN : -32768
SHRT_MAX : 32767
USHRT_MAX : 65535
INT_MIN : -2147483648
INT_MAX : 2147483647
UINT_MAX : 4294967295
LONG_MIN : -9223372036854775808
LONG_MAX : 9223372036854775807
ULONG_MAX : 18446744073709551615
LLONG_MIN : -9223372036854775808
LLONG_MAX : 9223372036854775807
ULLONG_MAX : 18446744073709551615

Applications

1. These macros are used to check integer overflow
2. They help a lot in computing minimum or maximum for an array by acting as a reference to check.

With this article at OpenGenus IQ, you must have got a complete idea of climits library in C++. Enjoy.