All language subtitles for 8. Challenge 2 - Sum of Digits in a Number

So in this challenge, what we are going to do is to write the recursive function that first of all,

what it will do is receive a number NUM.

And once it receives these num, all the recursive function task is to find out and return the sum of

all digits.

In this particular number.

So we simply take a given number.

It may of one digit two digits, three digit digits and so on.

And all these function has to do is to find out what will be the sum of all the digits.

So, for example, if we take NUM as 67, then we know that the sum of all of its digits will be six

plus seven, which is a total of 13.

Okay.

And the function, once it's found out, are all the sum of the digits.

The function simply should return 13.

In this example, any a for another example, we have NUM like nine thousand five hundred thirty one.

So the sum of digits is going to be pretty much calculated in the same way.

Right.

Because we use some recursive calls.

We divided to solve problems.

And it doesn't matter for us how many digits there will be in a given number as long as we know the

formula to how to divide it, to solve problems and make our recursive calls.

So in this case, if we want to know that some of these just we will simply sum up nine plus five plus

three plus one, which give us a total off of what it will be, the total of 18.

So that's pretty much the exercise.

We have to write the recursive function.

I know it's kind of tempting to use just thing for a loop to find out what will be the result.

Right.

Because we can use for a loop, so why wouldn't we use it?

Something that we know.

And the reason is very simple, because our task is to practice some recursive approach to find out

how can we divide, to solve problems are some bigger problem, and then to reach some base condition

or a stopping condition and to build up all our way up to find Venus the necessary result.

So take your time, guys.

Think about the solution.

Try to understand what will be the base case.

What will be the recursive calls?

And make me write also the the main function that will check out and makes sure that the recursive function

works as expected.

And then, of course, we are going to solve this exercise together.

So I'll see you there.