match-game | A drag-and-drop match game | Widget library

As part of a school project we are creating an application where users can match with each other if they play the same game. When you click on matchButton a random user that plays the game you have chosen will show up on the page. You can choose to like that user or continue hitting the matchButton to randomize another user.

Now we want to make sure that a user you have already liked won't be randomized and therefore not be rendered on the page.

The users that have been liked are saved in an array called match in the database, for each user. The users that play the same game are saved in an array called numOfMatches. So it is numOfMatches that we use to randomize a user.

I think I have to loop through numOfMatches and the match array in the database to see if the user in numOfMatches is already in the database. If so, I need to remove the user from numOfMatches so that it is not included in Math.random code.

I tried with this code in the last function in this post, but I am having a problem with understanding how to reach the elements in the match array in the users object and how to use splice (and in which function I should place the code since we use callbacks which I think is a bit tricky):