Basic Algorithm Scripting: Finders Keepers *Trying to understand if statements*

JavaScript
1

I am a little bit confused about the Finders Keepers assignment.

I already understand that using find() is the most efficient way to solve this problem.

But, before I learned about find(), I was struggling to come up with a solution.

This is the solution I thought would work, but it doesn’t:

function findElement(arr, func) {
  for (var i = 0; i < arr.length; i++) {
    let num = arr[i];
    func(num) === true ? num : undefined;
  }
}

From what I understand, I am testing if:

func(num) === true

And if that test evaluates to be true, num would be returned.
Otherwise, undefined would be returned because the test evaluated to false.

But no matter which functions I pass through, the ternary operator seems to only return undefined.

I would greatly appreciate any insight into this problem!

2

You’re not returning anything anywhere, the function will always return undefined

3 Likes
3

Also, you don’t want to return undefined after the first false because you won’t go through any remaining elements in the array.

1 Like
4

LOL Well. That was a big oopsy. I appreciate that.

5

Ahh! I’m pretty sure I get it now.

So using a ternary operator wouldn’t be useful here, because it will stop the for loop from iterating through the rest of the array.

6

Yes, if you are going to use it as the return statement then it will always return on the very first element in the array. I’m not saying you can’t use a ternary operator in this solution, just not the way you are currently using it.

1 Like
7

So this is my new solution:

function findElement(arr, func) {
  for (var i = 0; i < arr.length; i++) {
    let num = arr[i];
     if (func(num) === true) {
       return num;
     };
}
return undefined
}

moving

return undefined

outside of the for loop allows the iterations to continue through the array until the function evaluates to true.

1 Like
8

Also realized that since the functions being passed through findElement are boolean tests:

if (func(num) === true)

Can be condensed to:

if(func(num))

Now I understand how “Solution 1” was achieved! LOL

I appreciate you guys for the help!

9

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