Alphanumeric Codes

Why Alphanumeric Codes?  

- Computers must handle not only numerical data, but also letters, punctuation marks, mathematical operators, and special symbols.  

- Together, these form the complete character set of the English language.  

Definition  

- The complete set of characters or symbols is represented using alphanumeric codes.  

- Since computers understand only numbers, each character must have a numeric equivalent.  

Typical Alphanumeric Code Includes  

- 26 uppercase letters (A–Z)  

- 26 lowercase letters (a–z)  

- 10 digits (0–9)  

- 7 punctuation marks  

- 20–40 special characters  

ASCII – The Standard Code  

- The most widely used alphanumeric code is ASCII (American Standard Code for Information Interchange).  

- ASCII is a 7‑bit code, allowing for 128 possible combinations (2^7 = 128).  

- Each character (letter, digit, symbol) is mapped to a unique numeric value.