Text Representation

Published by Patrick Mutisya 10 months and 11 days ago

In computers, text is represented using binary, just like numbers, but with a fixed number of bits depending on the encoding.Each character (letter, digit, punctuation, etc.) is converted into a specific binary code that computers can understand and process.


Character Encoding

Character encoding is the process of converting characters into binary numbers. The most common character encodings include:

  • ASCII (American Standard Code for Information Interchange):
    • Uses 7 bits to represent each character.
    • Can represent 128 characters, including letters, digits, punctuation mrks, and control characters.
    • Example: The letter 'A' is represented as 65 in ASCII, which is 1000001 in binary.
  • Extended ASCII:
    • Uses 8 bits, allowing for 256 characters.
    • Includes additional symbols and characters used in different languages.
  • Unicode:
    • A more comprehensive encoding standard that can represent characters from almost all languages in the world.
    • Uses different bit lengths (8-bit, 16-bit, 32-bit) depending on the character set.
    • UTF-8 is a popular Unicode encoding that uses 8 bits for the most common characters but can use up to 32 bits for others.

Binary and Text

  • Binary to Text: Each character in a text string is converted into its binary equivalent using the chosen encoding system (e.g., ASCII or Unicode).
  • Text to Binary: The reverse process involves converting binary sequences back into readable text.

 

Examples

  • Example 1: ASCII Encoding
    • Text: "Hi"
    • ASCII Codes: H = 72, i = 105
    • Binary: H = 01001000, i = 01101001
    • Full Binary Representation: 01001000 01101001
  • Example 2: Unicode Encoding (UTF-8)
    • Text: "" (Euro sign)
    • Unicode: U+20AC
    • Binary: 11100010 10000010 10101100

Importance of Encoding

  • Consistency: Ensures that text is displayed correctly across different systems.
  • Internationalization: Allows software to support multiple languages and special characters.
  • Data Storage: Efficient encoding helps in saving space and ensuring data integrity during storage and transmission.

Common Issues in Text Representation

  • Mojibake: When text is displayed as random symbols because of incorrect encoding/decoding.
  • Character Set Mismatches: Occur when data encoded in one system is decoded using a different encoding standard, leading to unreadable text.