Nesting For Loops - "i is not defined" (but I think it is!)

Nesting For Loops - "i is not defined" (but I think it is!)
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I have run into an odd problem. Below is my solution for “Nesting For Loops”. It keeps coming back as “i is not defined”.

Here’s the kicker though, I have tried it within other javascript sandboxes and it comes out fine. It gives me the product number I expect.

So my question is, is there a flaw in my code that I am missing or could this be an error on FreeCodeCamps end?

function multiplyAll(arr) {
  var product = 1;

  for(i=0; i <arr.length; i++){
    for(j=0; j < arr[i].length; j++){
      product *= arr[i][j];
  return product;

// Modify values below to test your code

Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36.

Link to the challenge:


The example code in the challenge looks like this:

for (var i=0; i < arr.length; i++) {

Notice the word ‘var’ there? Try it and see if that helps.


Thanks that worked. Looks like I could have technically declared “i” without using “var” but it looks like thats not best practice. Risks making i a global variable.