How do I make a command to detect if there is 0 of a specific entity [closed]

Question

Me and my friend are making a world in bedrock edition about waves of zombies, and other entities. I need to make sure that there is 0 entities left to start the next wave. We tried many ways, such as "testfor", "execute unless", and we tried hooking up redstone to make it work. . . that didn't work. Please help.

Answer 1

execute unless is exactly what you're looking for, so you must've made an error in your command or elsewhere.

Here is an example on how to check for a lack of zombies.

execute unless entity @e[type=zombie] run say there are no zombies left.

If this is not what you need, please specify your question better.