Because that's for javascript, google how to print an array in C++

Doesn.t work in c++

put console.log(`arr = ${arr}`); as the first line in your function

And how do you use the console.log?

Spoiler flag!!!

I wonder why this code doesn't work

That's not kata issue, but problem with your code. (use question tag)

JavaScript Completions: 4265 (you can see at the top of this page or bottom of kata details page)

In short, your code is failing some tests, you can use console.log() to debug it and please read the error messages that are generated to help you.

console.log the input.

Is there any way to see the tests, or at least the ones that the code fails?