idIntegerReferred to as location_id elsewhere.
cityStringCity name
stateStringState name
countyStringCounty name
area_codeStringArea code name
populationIntegerThe city's population.
latitudeDoubleThe city's approximate central latitude.
longitudeDoubleThe city's approximate central longitude.

Shown here is the Location Search API in use inside the iExit Android app. This API returns an array of Location objects whose city values match the user's input.