UK area code 01708 (or +44 1708 in international format) is Romford.
An international number beginning with +1 708 is in the suburbs of Chicago, Illinois, USA.
(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.)
UK area code 01708 (a.k.a. +44 1708) is Romford.
The country code and area code of Romford, United Kingdom is 44, (0)1708.
Redwood City is in area code 650.
The village was established by the French in 1715, though a mission was in the area in 1708. It was turned over to the British in 1761.
Missouri City is in area code 281, with overlay code 832. There may also be some Missouri City numbers in area code 713.
Traverse City, Michigan, is in area code 231.
Rockwell City, Iowa, is in area code 712.
The area code for the whole Davao City is 082.
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.