Program to find factorial of Number in C++

What is a Factorial of a number 'n'?
 The factorial of a number 'n' is the product of all number from 1 upto the number 'n'
it is denoted by n!.  For example n=5 then factorial of 5 will be 1*2*3*4*5= 120. 5!= 120
Factorial program C++ Logic:
  • First think what is the factorial of a number? How mathematically it can be calculated.
  •  If you got this info then it will be very easier to make a C++ Program logic to find the factorial.
  •  User enters a number and we have to multiply all numbers upto entered number.
  • Like if user enters 6  then Factorial should be equal to factorial= 1*2*3*4*5*6.
  • In this case a for Loop will be very helpful. It will start from one and multiply all numbers upto entered number after it loop will be terminated.
  • Take a variable and initialized it to 1 and in loop store multiplication result into it like in below program a variable 
  • Factorial is used for this purpose.what is we does not initialized it to 1 and initialized it to zero or remain it uninitialized. In case of 0 our result will be zero in case of any number entered
  • In case of not initializing it our answer will correct mostly but if variable contains garbage value then we will not be able to get correct result. 
  • It is recommended that to initialize it to one.

C++ code to find prime number using for loop


using namespace std;

int main()


    int num,factorial=1;

    cout<<" Enter Number To Find Its Factorial:  ";


    for(int a=1;a<=num;a++)




cout<<"Factorial of Given Number is ="<<factorial<<endl;

    return 0;


Image View Of Program 

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