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Now that we know how to create objects, lets create more of them. First draw something that the player can pick up, like a couple of cherries. Go to the sprite editor and draw one in the next empty sprite tile.

Lets try to add that cherry into the scene by adding a table for the cherry and drawing it in _DRAW. We may randomize it's position with PICO-8's RND(X) function that will return a random value between 0 and X. 120 is appropriate because it be placed outside or on the bottom and right edges.

CHERRY={
 X=RND(120),
 Y=RND(120),
 DRAW=FUNCTION(SELF)
  SPR(2,SELF.X,SELF.Y)
 END
}

FUNCTION _DRAW()
 CLS()
 PLAYER:DRAW()
 CHERRY:DRAW()
END

When running the program with CTRL R it should show the cherry in a random position.

One cherry is fine and dandy, but what about adding more? Now we don't want to track more cherries with CHERRY2 and CHERRY3... that will get verbose quickly. We can use arrays instead and good thing LUA tables can be used as arrays as well! Create a table called CHERRIES and add new elements with PICO-8's ADD function.

So lets create a "factory function" that will create new cherries and add a table for all the cherries:

CHERRIES={} -- THIS TABLE WILL BE USED AS A LIST OF CHERRIES

FUNCTION ADD_CHERRY()
 ADD(CHERRIES, { -- ADDS THIS OBJECT TO THE CHERRIES TABLE
  X=RND(120),
  Y=RND(120),
  DRAW=FUNCTION (SELF)
   SPR(2,SELF.X,SELF.Y)
  END
 })
END

To initiate you'll need to call ADD_CHERRY several times, but you can only do it after the function was defined (as LUA executes the code as it evaluates it). To avoid this, lets use _INIT() function that will be called once LUA parser has gone through all the code, and put the initialization there.

Now we don't want to repeat ourselves (remember DRY?) so lets do a FOR-loop:

FUNCTION _INIT()
 FOR I=1,5 DO
  ADD_CHERRY() -- is called 5 times
 END
END

To draw the cherries we need to go over the array and call their drawing functions. There are two ways to do this, the simpler is to use indices in a FOR loop. Do keep in mind that LUA tables have their first element in index 1. Yes, LUA tables are not zero-based arrays!

To get the length of an array table, you prefix the variable with #. In the case for the cherries you write #CHERRIES to get the length. And now you can iterate over all cherries with a FOR loop between 1 and #CHERRIES.

All in all you'll get the following _DRAW function.

FUNCTION _DRAW()
 CLS()
 PLAYER:DRAW()
 FOR I=1,#CHERRIES DO
  CHERRIES[I]:DRAW()
 END
END

Try it out with CTRL R to see all the cherries in the scene being drawn.

An alternative way of going over a table is to use LUA iterators. PICO-8's API provides a couple ALL and PAIRS. The syntax is as follows if you only want to draw all cherries:

FOR CHERRY IN ALL(CHERRIES) DO
 CHERRY:DRAW()
END

• RND gives you random values
• Tables can also be used as array/lists
• ADD adds elements to a table
• Keep in mind that if you want to go over an array with FOR loop that the first index is at 1.
• You can also use LUA iterators to go over a table ALL or PAIRS. The latter will give entries in a KEY,VALUE pairs.