C Language program to calculate factorial of a number

Introduction: In this article i will explain how to create  a program to find/get/calculate factorial of entered number using For loop in C language.

Factorial:   Mathematically, the formula for the factorial is as follows. If n is an integer greater than or equal to 1, then

n ! = n ( n - 1)( n - 2)( n - 3) ... (3)(2)(1)

Rule: n! = n*(n-1)!

   So 1! = 1

        2! = 2×1 = 2

        3! = 3×2×1 = 6

        4! = 4×3×2×1 = 24

        5! = 5×4×3×2×1 = 120

        6!=  6×5×4×3×2×1 = 720

 or we can say if n=6 then factorial of 6 will be calculated as 1*2*3*4*5*6= 720 or 6*5*4*3*2*1=720.  So 6 != 720.

Implementation: Let's create a program to calculate Factorial of a number.

 #include<conio.h>

#include<stdio.h>

int main()

{
  unsigned long long int fact=1; 

  int i,n;

  clrscr();

  printf("Enter any positive number to calculate its factorial: ");

  scanf("%d",&n);

  for(i=1;i<=n;i++)

  {

    fact=fact*i;

  }

   printf("\nFactorial of %d = %llu",n,fact);

   getch();

   return 0;

}

Note:  We can also use 

  for(i=n;i>=1;i--)

  {

    fact=fact*i;

  }

instead of 

  for(i=1;i<=n;i++)

  {

    fact=fact*i;

  }

Now Run the program using Ctrl+F9

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How to check character is vowel or consonant in C language( Else if ladder or multiple else if )

Introduction: 

In this article I will explain how to check the character you entered is Vowel or Consonant using If-else Ladder in C.

A,E,I,O,U is known as Vowel and other alphabets are called Consonants.

#include<conio.h>

#include<stdio.h>

main()

{

       char ch;

      printf("Enter  any character between a to z : ");

      scanf("  %c",&ch);

                      if(ch=='a')

                            {

                            printf("%c  is vowel”,ch);

                            }

                      else if(ch=='e')

                            {

                            printf("%c  is vowel”,ch);

                            }

                      else if(ch=='i')

                            {

                            printf("%c  is vowel”,ch);

                            }

                      else if(ch=='o')

                            {

                            printf("%c  is vowel”,ch);

                            }

                        else if(ch=='u')

                            {

                            printf("%c  is vowel”,ch);

                            }                                

                    else

                           {

                            printf("%c  is consonant”,ch);

                           }

                    getch();

                    }

                   

 Run the program using Ctrl+F9

                   

Output:

First Run

 Enter any character between a to z : u

 u is vowel 

Second Run

 Enter any number between a to z : p

 p is consonant

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How to find greatest of two numbers using conditional operator in C Language

Introduction: 

Now in this article i will explain how to find greater between two numbers using conditional operator in C Language. Conditional operator is also known as ternary operator and its symbol is?
 The syntax for conditional operator is: condition? expression1:expression2;

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Find greatest of three numbers using nested if else statement in C Language

Now in this article we will learn how to find greatest of three numbers using nested if else statement in c language.

Implementation: Let's create a program to understand better.

#include<conio.h>

#include<stdio.h>

main()

{

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Swap two numbers without using temporary or Third Variable in C Language.

Introduction:

 In this article i will explain How to swap/interchange the values of two numbers using C language with an example program. In this program I’ll not use the third variable to swap numbers.

Implementation: let's create a program to swap the value of two numbers without using third variable.

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What is C Language? Write a program in c Language.

Introduction: 

What is C Language?

In computing C is a general purpose programming language developed by Dennis Ritchie at “AT & T’s Bell Laboratories” of USA in 1972.

This language was created for a specific purpose i.e. to design the UNIX operating system. The UNIX operating system and virtually all UNIX applications are written in the C language. C has now become a widely used professional language for various reasons which are:

·         Easy to learn

·         Structured language

·         It produces efficient programs.

·         It can handle low-level activities.

·         It can be compiled on a variety of computers.

Some Facts about C Language

·         C was basically invented to write an operating system called UNIX.

·         C language is a successor of B language which was introduced around 1970

·         The language was formalized in 1988 by the American National Standard Institute (ANSI).

·         C is a procedural language.

·         Today C is the most widely used System Programming Language.

·         C language influenced most of the modern world programming languages which include the mighty C++ and Java as well.

Now let’s create a program to calculate sum of two numbers using C language

#include<stdio.h>
#include<conio.h>
void main()
{
  int a,b,sum;
  clrsrc();
  printf("Enter value of a=");
  scanf("%d",&a);
  printf(" Enter value of b=");
  scanf("%d",&b);
  sum=a+b;
  printf("Sum of %d and %d = %d"a,b,sum);
  getch();
}

Run the program using ctrl+F9

Output will be:
Enter value of a= 50
Enter value of b= 30
Sum of 50 and 30 = 80

Difference b

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