Wanderlust randomizer challenge / links between .js files?

Maybe I have to go back a few topics as it may be about basic JavaScript, but here is what I don’t get.

I tried to randomize the venues retrieved by the Foursquare API by incorporating a randomizer function (shuffleArray()). Initially I put this function in main.js and later moved it to helper.js

main.js: https://gist.github.com/6ce457ab6c7ee86f87be9f0af4c05e7e

helper.js: https://gist.github.com/53c593aad56619d18ed10d36c0f66bff

What I am doing is creating a new variable randomizedArray in the renderVenues() function. As its value I’m assigning the outcome of shuffleArray() with venues as its argument. In the remainder of the renderVenues function this variable randomizedArray is not used but somehow when I refresh the webpage with the same location I get different venues. I would have expected to need the randomizedArray variable for assigning a value to the const venue and in the $destination.append() line. However when I do that I don’t get venue results on the webpage.
So how is it working?

And how are the helper.js and main.js linked to eachother? There is no export and import in the files?

If you’re not using something you could comment it out to see if the behaviour remains.
You could also test your function. You might for example start by describing what behavior it should have, and then call it and see if you can observe that behaviour.
You can use printing to write out what information you have before and after individual operations. If some value appears to be changing, you could look at where you are obtaining that value from.

I am such a dork. I don’t have to assign the outcome of the function shuffleArray() to a variable. My function shuffles the array venues in place. I am changing the order in the original venues array.