How to find the factorial of a number in C++
In this shot, we will discuss how to use a for loop to find the factorial of a number in C++.
The factorial of a number is the product of all the integers less than that number, until 1. The symbol that represents factorial is an exclamation point, i.e., !.
Let’s take a look at the following image to understand this better.
In the image above, we calculate the factorial of number 5. We multiply all the integers less than 5. The factorial of 5 is 120.
We will use the for loop to calculate the factorial of a number.
Let’s see the code snippet below to understand it better.
#include <iostream>using namespace std;int main() {int number, factorial=1 ;cin >> number;for (int i = number; i >= 1 ; i--){factorial = factorial * i;}cout << "The factorial of the given number is: " << factorial << endl;return 0;}
Enter the input below
Explanation
Enter a value in the above code to generate an output.
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In line 5, we initialize the
numberandfactorialvariables. -
In line 6, we take the input as
number. -
In line 7, we initialize a
forloop, where we give conditions to run the loop untili>=1and use a decrement operator to take the values in decreasing order. -
In line 9, whenever the loop iterates, the value is stored in
factorialuntil the loop gets terminated. -
In line 11, we print the factorial value of a number stored in the variable
factorial.
In this way, we can use loops to calculate the factorial of a number in C++.