Comprehensive Guide to Integer Data Types and Modifiers in C Programming

Today, we will continue our discussion on integer data type. Our outline for today's would be

to study modifiers such as short, long signed, unsigned

and some programming examples. Long and Short These are the modifiers used to

make it possible for a data type to take either less or more memory.

Suppose if size of integer is of 4 bytes in your computer, then using short in front of integer

makes it of 2 bytes. For example, In my computer size of short integer

is of 2 bytes. As you can see, the output is 2. On the other hand,

using long as a modifier in front of integer allows integer data type to take more memory space.

Here you can see, size of long integer is of 8 bytes.

Note: It is not guaranteed that short takes lesser memory than the integer

and long takes more memory than an integer. The only thing which is guaranteed is that, size of short is less than or equal to

size of integer and is less than or equal to size of long As I already told you in the previous lecture,

that integers can have signed range and unsigned range. Typically signed range is from

-32768 to +32767 and the unsigned range is from 0 to 65535

for 2 bytes integer. And for 4 bytes, this would be the range This is because in reality, most of the times

along with the positive values there is a need of representing negative values as well.

For example: When you are performing subtraction of 49 with 50, you will get -1 as the answer.

For representing these negative values in computer, you have different representations

and one of the widely used representation is 2's complement representation. Range of negative numbers

comes from this representation only. Apart form this that, there is one more important point

that we need to know. When you are declaring integer, with some variable name

then it is by default a signed integer variable. By putting unsigned modifier, in front of integer

it allows only positive values to be assigned to it Lets see what happens when we are trying to use these modifiers

in front of integer data type. I am going to provide 4 programming examples that will print

the range of integers when we apply different modifiers in front of integer data type.

Here is the first example. First of all, I have included a new header file limits.h

This header file consists of some symbolic constants that are useful in determining

the minimum as well as the maximum values of any data type according to the system. In this example,

I have used symbolic constant INT_MIN and assigned it to variable 1.

This symbolic constant gives me the minimum value of the signed integer according to my system.

And similarly, INT_MAX is assigned to variable 2 and this will give me the maximum value of signed integer.

Here, in this example we are trying to print the range of signed integer

writing int or signed int, both are one and the same thing, as I already told you.

because, by default integer is signed integer in our systems.

In my system, the size of integer is of 4 bytes. Therefore, range of signed integer

is from -2147483648 to +2147483647. In the second example, we are trying to print the range of unsigned integers.

here symbolic constant, maximum value of unsigned integer is UINT_MAX.

Also, there is no symbolic constant available in limits.h header file, for minimum value of unsigned integer.

Because minimum value is fixed for all systems and that is zero.

And there is one more important thing to note Here to print the value of an unsigned integer, we have to use %u

instead of %d. As %d is used to print decimal value, %u is used to print unsigned decimal value.

Now as we can see, the output is range of unsigned integer is from 0 to 4294967295.

As for 4 bytes or 32 bits unsigned integer maximum value is 2 raised to the power 32 - 1 which is 4294967295.

In the third example, we want to print the range of short signed integer.

Symbolic constants for getting the minimum as well as the maximum values of short signed integer is

SHRT_MIN and SHRT_MAX respectively. Because of this "short" key word, integer data type takes 2 bytes

instead of 4 bytes. Therefore range would be from -32768 to +32767.

And finally, in example no. 4 we are using USHRT_MAX for getting the maximum value

of unsigned short integer. And as expected, the range is from 0 to 65535.

Note: You can also write unsigned short instead of short unsigned here. The order doesn't matter.

You can also check the range of long integers by replacing the keyword short with long.

And in printf, instead of using %d, you can use %ld for long signed integer

and instead of %u you have to use %lu. There is one more thing called

long long integer. It simply means, Suppose if long integer is of 4 bytes,

then long long integer will be of 8 bytes else if long integer is of 8 bytes,

then long long integer would be of 8 bytes only. Because the maximum limit is upto 8 bytes you can say.

Let's try to summarize the information that whatever we had learnt till now. sizeof(short) is less than or equal to

sizeof(int) and is less than or equal to sizeof(long) Writing signed int some_variable_name; is equivalent to writing

int some_variable_name; %d is used to print "signed integer" %u is used to print "unsigned integer"

%ld is used to print "long integer" which is actually equivalent to signed long integer.

%lu is used to print "unsigned long integer" %lld is used to print "long long integer" %llu is used to print "unsigned long long integer"

OK friends, this is it for now. See you in the next lecture.