Detecting items in a Dropper

I am standing on a dropper facing upwards, with 64 stone blocks in the top-left slot, and I am running this command:

/testforblock ~ ~-1 ~ dropper 1 {Items:[{Count:64,Slot:0,id:stone}]}

but for whatever reason, it returns:

the block at (coords) does not have the required NBT keys.

Best Answer

Count and Slot are both bytes, so need a 'b' after them. You also need to specify the full item name:

/testforblock ~ ~-1 ~ dropper 1 {Items:[{Slot:0b,id:minecraft:stone,Count:64b}]}

A dropper can be used to eject items, or push items into another container.

Players will need the following items to make an automatic item dropper:

Three redstone dust.

one repeater.

one comparator.

one dropper.

four building blocks.

Chest and hopper (optional)

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