• Please check this below program which prints even numbers from 1 to n.

• Print even numbers in c 
• To print sum of even numbers from 1 to n first we need to get all the even numbers and add them.
• Using for or while loop iterate from 1 to n number and get all even numbers
• sum=sum+evenNumber
• C program to find sum of even numbers using while loop

C program to find sum of even numbers using while loop

• Lets see how to write a c program to print even numbers using c programming.\
• Its a basic example to print only even numbers 
• Use for loop and iterate from 1 to n.
• In each iteration check if number if divisible by 2 (n%2 == 0). if yes then its a even number otherwise it is a odd number.
• C program to print even numbers from 1 to n. 

#2 print even numbers in c using while loop

• Now we will try to print even numbers using while loop
• Only difference is replace for with while loop
• Variable initialization will be done before loop
• condition will be inside while(condition)
• increment or decrement will be last line of while block 
• Lets print even numbers using while loop from 1 to n.

• To find sum of digits of a number in c , we need to get individual numbers and add those numbers.
• First of all read a number from user using scanf.
• Using while loop get individual number 
• Divide the number with 10 so we will get last digit of that number as remainder , once we get that last digit then add it to one variable and divide that number with 10 so it will become one digit less.
• like this we can get all digits and add all those numbers to get sum of digits 
• Sum of individual digits in c program
• c program to find sum of digits of a 3 digit number

correction: here n =number .

# program to find sum of digits of a number in c

1. #include<stdio.h> // include stdio.h
2. //c program to find sum of digits of a number using while loop
3. //write a program to find sum of digits of a number
4. //www.instanceofjava.com
5. int main()
6. {
7.     // declare variables 
8.     int number, remainder, sum = 0;
9.     //read input from user 
10.     printf("Enter a number: ");
11.     scanf("%d", &number);
12. 
    
13.    //iterate until number not equal to zero
14.    // get individual digits and add all those digits to get sum
15.     while(number != 0)
16.     {
17.         remainder = number % 10;
18.         sum += remainder;
19.         number = number / 10;
20.     }
21.   //print sum of digits in c
22.     printf("sum = %d", sum);
23. 
    
24.     getch();
25. }

 Lets discuss a basic c program

• Sum of two integers using c. This might be the first practice program for all users.
• To check sum of two integers , read input from user and store in two corresponding integer variables.
• Also take one more variable to store result of sum of two numbers
• c= a+b
• Print result using printf

• To check GCD of two numbers first we need to read input from user. i.e ask user to enter two numbers
• Store those two numbers in two integer variables
• Check if number is factor of given two numbers by iterating in for loop.

 c program to check whether the triangle is right angled triangle

• To check right angle triangle or not first we need to check sum of all three angles 
• If sum of all three angles is 180 then we it should satisfy second condition also
• Second condition is on of the angle should be 90.
• if both the conditions are passed then we can say it is a right angle triangle.
• Now lets write a c program to check triangle is right angle triangle or not.