Most efficient way to index through an array, skipping nulls

Question

Hi folks
I am trying to implement a hotbar for my player inventory (game is played on controller) thus they use RB/LB to navigate the hotbar, but I want the $$anonymous$$ghlighter to skip to the next spot with an item, ignoring empty spots. I am pretty sure Minecraft works t$$anonymous$$s way, so you have an idea of what I'm trying to do.

Anyway, I have written the following block of code that is called in my Input function that is called in Update, so t$$anonymous$$s is happening every frame. I am afraid that t$$anonymous$$s is an inefficient way to handle t$$anonymous$$s, but I can't t$$anonymous$$nk of a better way to do t$$anonymous$$s.

My code below appears to work fine but I fear checking t$$anonymous$$s every frame is bad If anyone has any insight or ideas it would be much appreciated!

         if (rightBumperBool)
         {
             for (int i = inventoryIndexer; i < gunInventory.Length-1; i++)
             {
                 if (gunInventory[i + 1] != null)
                 {
                     inventoryIndexer = i + 1;
                     break;
                 }
             }
         }
         if (leftBumperBool)
         {
             for (int i = inventoryIndexer; i > 0; i --)
             {
                 if (gunInventory[i - 1] != null)
                 {
                     inventoryIndexer = i - 1;
                     break;
                 }
             }    
 
         }

Answer 1

Best Answer

Answer by IvanC314 · Oct 14, 2022 at 08:17 PM

Your code seems pretty fine as long as you turn your bools rightBumper and leftBumper back to false after they are turned true as to stop the for loops from running more than once. I don't t$$anonymous$$nk there's an issue with your code but you could try using getinput

 Update()
 {
     if (Input.GetKeyDown(KeyCode.RightArrow))
     {
         for (int i = inventoryIndexer; i < gunInventory.Length - 1; i++)
         {
             if (gunInventory[i + 1] != null)
             {
                 inventoryIndexer = i + 1;
                 break;
             }
         }
     }
     else if (Input.GetKeyDown(KeyCode.LeftArrow))
     {
         for (int i = inventoryIndexer; i > 0; i--)
         {
             if (gunInventory[i - 1] != null)
             {
                 inventoryIndexer = i - 1;
                 break;
             }
         }
     }

You can switch the keycodes out to your preferred buttons. Getting input is fine in update. Hope t$$anonymous$$s helps.

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justinurie · Oct 14, 2022 at 08:28 PM 1

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The bools are already doing GetKeyDown essentially and only are True for exactly 1 frame then revert to 0, so I guess I am doing everything right :)

thank you!

Most efficient way to index through an array, skipping nulls

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