JavaScript Discord Bot - Unable to Delete User ID from Array

Other Questions Discord bot
1

I’m working on a Discord bot that tracks online users, but I’m having trouble removing user IDs from my array when they go offline.

client.on("presenceUpdate", (previousPresence, currentPresence) => {
  if(previousPresence.status !== currentPresence.status){
    const userID = currentPresence.user.id;
    if(currentPresence.status === "online"){      
      activeUsers.push(userID);
      console.log("-------user online--------");
      console.log(activeUsers);
    }else
    if(currentPresence.status === "offline"){
      activeUsers.filter(id => id !== userID)
      console.log("-------user offline--------");
      console.log(activeUsers);
    }
      console.log(`${currentPresence.user.username} status changed to ${currentPresence.status}`);
  }
});

The issue is that user IDs aren’t being removed from the array. Here’s what I see in the console:

-------user offline-------- []
-TestUser- is now offline
-------user online-------- [ '203287818330570752' ]
-TestUser- is now online
-------user offline-------- [ '203287818330570752' ]
-TestUser- is now offline
-------user online-------- [ '203287818330570752', '203287818330570752' ]
-TestUser- is now online

As you can see, the ID stays in the array and even gets duplicated. What am I doing wrong?

2

The issue is that filter creates a new array instead of changing the original one. You need to assign the result back: activeUsers = activeUsers.filter(id => id !== userID); and it’ll work properly. I made this exact mistake building my moderation bot last year - wasted hours debugging before I realized I wasn’t reassigning the filtered array. The duplicates happen because you’re adding users multiple times without checking if they’re already there.

3

Your filter method isn’t working because you’re not reassigning the result. The original array stays unchanged. Fix it with activeUsers = activeUsers.filter(id => id !== userID). Also, check for duplicates when users come online using if (!activeUsers.includes(userID)) before pushing to the array. Had the same issue with my first Discord bot - took me forever to figure out.

4

yep, filter doesn’t change the original array, ya gotta save it back. or use splice: activeUsers.splice(activeUsers.indexOf(userID), 1) but don’t forget to check if indexOf isn’t -1 first or it’ll screw up your array.