Unsigned Int in C

Last Updated on March 31, 2023 by Prepbytes

In any programming language, there are multiple data types available. The programmers use data types to store the value of the data according to its requirement and we can store the data in many data types like integer, character, string, float, boolean, etc. One of the most significant data types is unsigned int in C language. We can use it to store non-negative values. It is similar to an integer but with a basic difference. While proceeding further in this blog we will learn all about unsigned int in c, its examples, and its applications.

What is Unsigned Int in C?

As the name suggests unsigned int in a C programming language is a datatype that represents an integer value without a sign. It can hold zero, and positive integers but it is not allowed to store or hold negative values. The unsigned int in c is commonly used to represent the values that are non-negative like the number of iterations of the loop, and the size of the array.

The unsigned int in c is defined in stdint.h header file, which is already included in most of the c programs. The general size of the unsigned int in c is 4 bytes but it can vary according to the system and compiler architecture.

Syntax of Unsigned Int in C

The general syntax for declaring an unsigned int in c is to use the keyword unsigned int followed by the variable name you want to give it. Like shown below.

unsigned int count;

Like in the above declaration we have created a variable named count of type unsigned int.

To initialize the unsigned int in c we can use the assignment operator and then assign the required value. Like we have shown below.

unsigned int count = 10;

We have initialized the value of the count to 10.

Unsigned Int Range

The range of unsigned int in c is not defined, it depends on the number of bits we are using to represent the variable. Like if an unsigned int inc is represented using 32 bits then it can hold the value from 0 to 4294967295.

We can calculate the range of values that an unsigned int in c can hold by using the following formula.

2^n - 1

Where n is the number of bits used to represent the unsigned int.

For example, if an unsigned int is represented using 16 bits, the range of values it can hold is:

2^16 - 1 = 65535

Similarly, if an unsigned int is represented using 8 bits, the range of values it can hold is:

2^8 - 1 = 255

Examples of Unsigned Int in C

Here are some example programs that demonstrate the use of unsigned int in C programming:

Example 1 of Unsigned Int in C: Counting from 0 to 10 using unsigned int
In this section we will implement the above-mentioned example.

#include <stdio.h>
int main()
{
unsigned int count = 0;
while (count <= 10)
{
printf("%u\n", count);
count++;
}
return 0;
}

Output

0
1
2
3
4
5
6
7
8
9
10

Explanation of the above example
In the above program, an unsigned int variable named count is initialized with the value 0. A while loop is used to count from 0 to 10, and each value of count is printed using the printf function. The %u format specifier is used to print an unsigned int value.

Example 2 of Unsigned Int in C: Finding the size of an array using unsigned int
In this example we will find the size of an array using unsigned int in C.

#include <stdio.h>
int main()
{
int arr[] = {1, 2, 3, 4, 5};
unsigned int size = sizeof(arr) / sizeof(arr[0]);
printf("The size of the array is %u\n", size);
return 0;
}

Output

The size of the array is 5

Explanation of the above example
In the above program, an array named arr is declared and initialized with 5 integers. The size of the array is calculated using the sizeof operator and stored in an unsigned int variable named size. The size of the array is then printed using the printf function with the %u format specifier.

Example 3 of Unsigned Int in C: Converting a signed int to an unsigned int
In this section we will see the code implementation of the above-mentioned example.

#include <stdio.h>
int main()
{
int num = -10;
unsigned int unum = (unsigned int)num;
printf("Signed int value: %d\n", num);
printf("Unsigned int value: %u\n", unum);
return 0;
}

Output

Signed int value: -10
Unsigned int value: 4294967286

Explanation of the above example
A signed int variable called num is initialized with the value -10 in the program above. The num variable is then kept in the unum unsigned int variable after being typecast into an unsigned int. The printf function is then used to output the values of both variables using the %d and %u format specifiers, respectively.

We can see from the data above that the signed int variable’s value is different from the unsigned int variable’s value. This is so that the signed int number can have a negative value, which an unsigned int cannot.

Applications of Unsigned Int in C

The unsigned int in a C programming language has many applications some of which are mentioned below:

• We can use it to represent the size of the array as the size of the array must need to be zero or positive.
• We can use them in bitwise operations where the binary representation of the number is important.
• We can use unsigned int in c to store flags, where each bit represents a different flag.
• We can use them in dynamic memory allocation to allocate a specific amount of memory.
• It is also used in cryptographic algorithms for representing keys, ciphertexts, and other cryptographic values.

Conclusion
In this article, we learned about the unsigned int data type in C programming. We discussed the declaration and initialization of unsigned int variables, the range of values that an unsigned int can hold, and demonstrated some example programs. It is important to use the appropriate data type for your variables in C programming to avoid errors and unexpected results. The unsigned int data type is useful for representing non-negative values, such as the size of an array or the number of iterations in a loop.

Frequently Asked Questions

Here are some of the frequently asked questions about unsigned int in c.

1. What happens if you assign a negative value to an unsigned int variable?
If you assign a negative value to an unsigned int variable, it will wrap around and become a large positive value. For example, if you assign -1 to an unsigned int variable, it will become the maximum value that the unsigned int can hold.

2. Can you use arithmetic operations with unsigned int variables?
Yes, you can use arithmetic operations with unsigned int variables. However, be careful when using subtraction or division, as these operations may produce unexpected results.

3. Can you compare signed int and unsigned int variables in C programming?
Yes, you can compare signed int and unsigned int variables in C programming. However, be careful when comparing variables of different types, as the results may be unexpected.

4. Can you use unsigned int variables in control structures like for loops and while loops?
Yes, you can use unsigned int variables in control structures like for loops and while loops.

5. Can you use negative values with the modulus operator and unsigned int variables in C programming?
No, you cannot use negative values with the modulus operator and unsigned int variables in C programming. The result will be undefined.