Integer Value Ranges in C : Capacity and Compatibility

While working with integer types in C , it's crucial to understand the range of values they can store. This knowledge helps ensure that you select the appropriate type for your specific requirements.

The minimum ranges guaranteed by the C standard for common integer types are as follows:

• short int and int: -32,767 to 32,767
• unsigned short int and unsigned int: 0 to 65,535
• long int: -2,147,483,647 to 2,147,483,647
• unsigned long int: 0 to 4,294,967,295

These ranges indicate that unsigned long int cannot reliably store a ten-digit number (1,000,000,000 - 9,999,999,999) on a 32-bit computer as it exceeds the maximum representable value of 4,294,967,295.

However, a larger type, long long int, was introduced in C99 and C 11 to handle wider integer values. The minimum range for long long int is:

• long long int: -9,223,372,036,854,775,807 to 9,223,372,036,854,775,807
• unsigned long long int: 0 to 18,446,744,073,709,551,615

This extended range allows long long int to comfortably accommodate ten-digit numbers. Note that the availability of long long int is compiler-specific, so it's essential to check its support in your environment.