count is a primitive that reports the number of agents in a given agentset. For example, count turtles reports the total number of all the turtles in a model, while count turtles with [color = green] reports the number of green turtles in the model. You can use count with turtles, patches, and links.

We can also use count with turtle breeds and link breeds such as count dogs or in combination with other reporter agents primitives such as count turtles-here.

In the model example below, we have a dog park at the center and we have a bunch of turtles that represent the dogs in a neighborhood. Our dogs move around completely randomly. When there are more than 5 dogs in the playground at any given time, our model shows a "Playground is too crowded" message.