How can I print the sum of even numbers from a user input ?

Question

if a user inputs 10.how can I print the sum of even numbers from 1 to 10.

Answer 1

@luka
I assume you meant to put the if statement inside the loop 😝. Otherwise your still adding odd numbers.

Another way would be to make the for loop include even numbers only.

for(int i = 2; i <= input; i += 2)

Answer 2

Or you can use math
The sum of the first n even numbers = n * ( n + 1 )

If the user enters 10, half of these are odd numbers, so you divide it by 2. ( and round it down if you have to )

5 * 6 = 30