In the UK, area code +44 1243 (or 01243 within the UK) is Chichester.
An international number beginning with +1 243 is in North America (USA, Canada, etc.; country code +1), but there is no area code 243.
There may be other countries with domestic area codes like 1243 or 01243.
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, and many other countries use different prefixes.)
The country code and area code of Chichester, United Kingdom is 44, (0)1243.
1243
Redwood City is in area code 650.
Missouri City is in area code 281, with overlay code 832. There may also be some Missouri City numbers in area code 713.
The area code for the whole Davao City is 082.
Traverse City, Michigan, is in area code 231.
Rockwell City, Iowa, is in area code 712.
Johnson City, NY, is in area code 607.
The area code 479 is for the state of Arkansas. A zip code is for a city or part of a city. By area code alone you cannot determine a zip code.
Gotham City is a fictional place, and thus has no actual area code.
It has the area code 082.
Area code 609 is in New Jersey, including Atlantic City, Trenton, and Princeton.