In a similar way to SQL, you can compute aggregates with Cypher. The main difference with SQL is that there is no need to use a GROUP BY statement; all fields that are not in an aggregation function will be used to create groups:
MATCH (FL:State {code: "FL"})-[:SHARE_BORDER_WITH]-(n)
RETURN FL.name as state_name, COUNT(n.code) as number_of_neighbors
The result is the following one, as expected:
╒════════════╤═════════════════════╕
│"state_name"│"number_of_neighbors"│
╞════════════╪═══════════...
