I want to know how does this program make results in simple way

Curriculum Help
1

Tell us what’s happening:

  **Your code so far**


function sum(arr, n) {
// Only change code below this line
if (n <= 0) {
return 0;
// Only change code above this line
} else {
return sum(arr, n - 1) + arr[n - 1];
}
}

  **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 10.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.190 Safari/537.36.

Challenge: Replace Loops using Recursion

Link to the challenge:

2

I’m not sure I understand your question. You have pasted in the correct answer for the challenge. Do you understand the code you pasted above?

3

I do not understand it

4

Recursion has been discussed so many times in this forum that I’m not exactly excited to type out a long explanation here :slight_smile: Search for “recursion” using the search icon at the top of the forums here and you will find a ton of links to previous discussions about recursion.

But maybe someone else will feel differently and type something up here?

mohameddawoud912 5

FireShot Capture 014 - I want to know how does this program make results in simple way - Jav_ - forum.freecodecamp.org

1 Like
6

Explain to us what is going on in this return statement. Let’s use the following as an example. You initially call the function as:

sum([0, 1, 2], 3);

What will that return statement look like (fill in the actual values)?

7

I want to know what does this function do with this elements

8

And I am trying to help you understand this by leading you through how the function works. So if we start with the initial function call of

sum([0, 1, 2], 3);

We will hit the else statement and thus do the following:

return sum(arr, n - 1) + arr[n - 1];

Replace all the variables in that return statement with the actual values.

9

I am trying to understand what is the different between the add sign and the miltiply sign

10

+ adds two things together, usually numbers (2 + 2 = 4), but in JS it can also concatenate strings ("a" + "b" = "ab").

* multiplies two numbers (2 * 3 = 6).

I’m not sure if this is what you were asking or if you meant something else?

11

I mean the sign in ```
return multiply(arr, n - 1) * arr[n - 1];

addition
return sum(arr, n - 1) + arr[n - 1];
12

The addition sign in this return statement adds two numbers. Using my example above, what is the value of arr[n-1]? And then you are adding that value to what is returned by the function call sum(arr, n - 1). Again, using my example above, fill in the actual values for the return statement in the else block when you call it for the first time.

13

thinks you for spending time to help me