Chapter 2

Chapter 2

1. Primatives

   • Numbers
     • Byte (8 bit) SMALLEST
       • Short (16 bit)
         • int (32 bits)
           • long (64 bit) LARGEST
     • Decimals
       • float (32 bit)
         • double (64 bit)
   • char (single Unicode character)
   • boolean (T/F)

2. Variables

   • Reference Types (contains object reference)
   • Primitive Type (contains primitive)
     • Primitive Conversions
       • Widening Conversion (converting to type of same size or larger)
       • Narrowing Conversion (converting to type with smaller size)
         • may cause data loss
   • Sun's Naming Con: start lowercase, no symbols
   • Constants (unchangeable/static variables)
     • use "final" to deem constant
   • Literals
     • convention of declaring types and values of variables
     • Primitive Literals
       • used for int, short, long, byte
         • Long type literals need "L" at end of value
           • i.e. long a = 123456789L
         • Float (use f or F at end of value)
         • Character Literals (char encased in single quotes)
           • Can use \ to make escape sequences
             • E.X. \b (backspace) \t (tab) \" (quotes)...

3. ASCII

   • 7 bit characters

4. Unicode

   • 8, 16, and 32 bit characters
   • Seperators
     • () method signatures, expressions, conversions, loops
       • {} type declaration, array creation, blocks
         • [] array declaration, array value dereferencing
           • <> pass parameterized types
             • ; terminate statements, for loop conditions
               • . separates package names

5. Operators

   • Unary
     • only one operand
       • - + ++ -- ! ~
   • Arithmatic
     • + - * / %
       • % Modulus (returns remainder of division)
   • Conditional/Relational
     • == != (for int, float, bool, char)
       • < > <= >=
     • && (and)
       • || (or)
         • ? : (uses three expressions)
           • expr1 ? expr2 : expr3
           • expr1 must be boolean
             • if expr1 TRUE, return expr2
             • if expr1 FALSE, return expr3
   • Shift/Logical
     • << >> >>>
       • shifts int place depending on left or right shift
   • Assignment
     • += -= *= ....
   • Other
     • Unary normally converts to int
       • use type in () to stop conversion