C program for factorial – 2025

What is the C program for factorial?

The AC program for factorials calculates the product of all positive integers from 1 to a given number. For example, the factorial of 5 is 1 * 2 * 3 * 4 * 5, which is equal to 120. This program is useful for learning because it teaches to use a loop or recursive function to perform repeated multiplication. By understanding C programs for factorials, beginners can learn important programming concepts such as loops, recursion, syntax, and more.

Requirements to know

There are some pre-requisites that need to be known before starting a C program for factorial. These pre-requisites will not only enhance your understanding of the program but also make the learning process easier.

Among these requirements are the following:

how to write a c program for factorial

We can write a C program for factorial using the two methods listed below. Both methods listed below have their own advantages and disadvantages. Let’s learn about both methods in detail with the help of code so that you can understand better.

• The use of loops
• The use of recursion

1. C program for factorial – using loops

Using a loop is a straightforward and simple way to calculate the factorial of a number. This method involves declaring a variable to store the result and then using a loop to multiply this variable by each integer up to the desired number. This approach is easy to understand and apply, which makes it ideal for beginners.

Why do you want to use this method?

• Simple and easy to understand.
• Skilled in calculating factorials of small numbers.
• It does not require understanding of recursive function calls.

Inserting C program #sh for factorial using loops

#sh to match/ / Function to find the factorial of a given number main entry point () int n, i; unsigned long long fact = 1; / / factorial can be a large number, so we use unsigned long long in place of int. Printf (Enter an integer:) Scanf (% d, & n) / / Check if the user entered a negative number If (n < 0) Printf (“Error! The factorial of negative number does not exist. “) Other { for (i = 1; i < = n; + + i) fact * = i; / / fact = fact * i; } fact * = i; / / fact = fact * i; } return of 0. }

Output Enter integer: 5 Factorial of 5 = 120.

Using recursion is a more advanced technique where a function calls itself to compute the factorial. This method basically shows the power of the recursive function call. It involves defining a base case for the smallest input and a recursive case that breaks the problem into smaller parts.

Why do you want to use this method?

• A clear and concise method.
• Useful for the performance and practice of repetition.
• Provides an in-depth understanding of function calls and stack frames.

Inserting C program #sh for factorial using recursion

#sh to match/ / function prototype Unsigned long factorial (int n) main entry point () int n; Printf (Enter an integer:) Scanf (% d, & n) / / Check if the user entered a negative number If (n < 0) Printf (“Error! The factorial of negative number does not exist. “) Other printf (factorial of% d =% llu, n, factorial (n)) return of 0. } / / Recursive function to find the factorial of a number / / Recursive function to find the factorial of a number If (n = 0) / / Base case a return to 1; Other return n * factorial (n-1) / / recursive case }

Output Enter integer: 5 Factorial of 5 = 120.

Both methods are valuable tools in a programmer’s toolkit, and understanding them will enhance your ability to deal with various programming challenges.