Give three codes for alphanumeric characters?

ASCII, or the American Standard Code for the Information Interchange, is the name of a character-encoding scheme based on the English alphabet. Codes in ASCII represent text in computers and communication devices that use text.

UTF-8 is another coding system and has recently become the dominant character coding type for the World Wide Web.

Example:

In UTF-8, the four character string "I♥NY" is encoded (shown as hexadecimal byte values): 49 E2 99 A5 4E 59.