Wikipedia has a listing of all area codes. You can find a link to the US list below.
Which country did you want? Link to the UK list added.
It depends on what country. There are lists of STD Codes (telephone area codes) for different countries on a variety of websites. See the related links below for a few examples.
Yes, different countries usually have different country codes, and each country code can have its own system of area codes.
There are about 300 area codes in the United States, plus 30 in Canada and 20 in other countries and territories in or near the Caribbean.
www.wtng.info is the most comprehensive resource for this.
Traffic Conference Area 3 includes countries in the African region. Key countries in this area are Algeria (Algiers), Egypt (Cairo), Kenya (Nairobi), Nigeria (Abuja), and South Africa (Pretoria). Each country has its own unique codes for various purposes, such as ISO country codes and vehicle registration codes. For example, the ISO codes are DZA for Algeria, EGY for Egypt, KEN for Kenya, NGA for Nigeria, and ZAF for South Africa.
There are various countries that might have 077 as an area code for domestic calls, or that have area codes beginning with 077. You need to be more specific.
Your question is not clear. "STD codes" (Subscriber Trunk Dialling) is another term for telephone area codes in some countries, including the UK, Ireland, India, Pakistan, South Africa, and other formerly British countries around the world. There are tables of area codes for each country. See the related links below for examples.
The Nile River flows through several countries, each with its own telephone country code, and flows through several different area codes within those countries.
Only two countries use ZIP Codes: the United States and the Philippines. Many other countries have postal codes that use other names (postcodes, PIN Codes, etc.). Some countries do not use postal codes at all.
See the links below for three that are accurate and up-to-date as of late 2010. Beware that other many online lists are a decade or more out of date.
Area codes in the United States and Canada were originally assigned in 1947 by the Bell System. New area codes are assigned by the North American Numbering Plan Administration, in consultation with state and provincial regulators. Area codes in the United Kingdom were originally assigned by the post office, which was responsible for developing the telephone system. New area codes are assigned by Ofcom.
appendix "D" in the CPT manual lists all add-on codes.