Find element in array using recursion - javascript

Question

I'm trying to select Nth element from array using this function:

function nthArr(arr, index){
 if (index === 0)
 return arr[index];
 else nthArr(arr.slice(1), --index);
}
nthArr([1,2,3,4,5,6],3)

I would await that it returns 4, but instead I get 'undefined'.
How should I return correct value?

• Biffen: Shouldn't there be a return somewhere after else?
• John Bupit: Ummm... but why? Doesn't arr[index] work for all indices anyway?
• Onilol: @JohnBupit arrays[] are accessed by index

Answer 1

You are missing a return statement in the else branch.

if (index === 0)
 return arr[index];
else {
 return nthArr(arr.slice(1), --index); // Note the return
}

• borism: exactly - my java habits :-)

Answer 2

You're missing a return statement...But why not just simplify the whole thing?

function nthArr(arr, index){
 return arr[index];
}
var result = document.getElementById('result');
result.textContent = nthArr([1,2,3,4,5,6], 3);

<span id="result"></span>

• borism: yes this is simpler, but I needed it for traversing list object