Chapter 9
Section 1
"Characters"

- data type char reperesents a single character
- write character constants as symbols enclosed in single quotes
- internally, characters are encoded as an arbitrary combination of 1s and 0s
- ASCII
  - American Standard Code for Information Interchange
  - widely used character coding scheme
  - not all characters are printable
  - 128 total characters
    - requires 7 bits for representation
    - 1 byte is actually used
    - 128 leftover codes are generally used for manufacturer-specific non-standard symbols
  - sufficient for common English, but not for many other languages
- Unicode
  - full name is Unicode Worldwise Character Standard
  - established by the Unicode Consortium
  - 34,168 distinct characters
  - sufficient for non-English languages
  - 2 bytes per character
  - same as ASCII codes where overlap
  - used by Java for char data type
- to use Unicode for IO, the OS and development tool must be able to handle it
- declaration
  - char <name> = <literal>;
- casting a character to an integer returns the ASCII code
- casting an integer to a char shows the char associated with a given ASCII code, assuming the int is between 0 and 127
- compare characters as you would numbers
  - relative value determined by relative value of ASCII code
  - capital letters sort before lower case
  - within a case, letters sort alphabetically

Quick Check
1. a. A
   b. 67
   c. Y
   d. ?
2. 256