Searching for an even number

Checks in loops are very convenient. They allow you to do checks at each iteration of the loop.

For example, we will check whether the number i is now even in the loop from previous tasks. If the number is even, we will add 2 to the sum, and if the number is odd, we will add 1.

How can I check if the number is even? Here the operator % can help. It is called the remainder in division and, as the name implies, returns the remainder in division.

10 % 5;  // Returns 0
12 % 5;  // Returns 2
7 % 3;   // Returns 1
5.5 % 2; // Returns 1.5

How does this help in determining an even or odd number? An even number is divided by 2 without remainder. Therefore, if the division i% 2 returns 0 the number is even, otherwise the number is odd.

Let’s write a check using % in our loop.

By the way, the value returned by the operator % is the same as the remainder in division in arithmetic. This division is easier to understand on an everyday example. Imagine that you have 13 chocolates, and there are 4 people (including you). How to divide the chocolates among everyone so as not to offend anyone? It’s not possible to divide the chocolates equally, because 13 cannot be divided by 4 without fractional parts. But 12 can be equally divided by 4. You can give 3 chocolates to everyone. Then you will give out 12 chocolates and there will still be one left, because initially there were 13 chocolates. This left-over chocolate is the remainder in division.