CSC152 2005S, Class 10: Numeric Values in Java

Admin:
* Questions on the homework?
* No reading for tomorrow
* Today is something of a "basics" lab (no interesting questions as you had with strings)

Overview:
* Brief overview of numbers
* Lab!

/Questions on the Homework/
* Due at 11:00 a.m. on Wednesday.
* You have permission to forge the timestamp on your messages

/Numbers in Java/
* Need to represent numbers
* Java designers:
  * Support efficient computation when the programmer wants it
    (fairly close to hardware in representation and computation)
  * Support elegant, object-oriented computation for those who care more about style
* Lots of different representations
  * Primitive types (efficient)
    * Fixed number of bits for each type of number
      * 8 bits, 16 bits, 32 bits, 64 bits
    * One of two "kinds" of numbers: integers or reals
      * 8 bit integer: byte
      * 16 bit integer: short 
      * 32 bit integer: int 
      * 64 bit integer: long
      * 32 bit reals: float
      * 64 bit reals: double
  * Object types that correspond to primitive types
    Byte, Short, Integer, Long, Float, and Double
    * Mostly inter-convertable
    * Include some amount of overhead for "look, this is an object" (I have no idea how much that is, but assume it's at least 64 bits)
  * "Big" numbers: Larger range of values (more precise for reals)
    BigInteger, BigDecimal
    * The storage space depends on how big the value is
* Primitive types support "infix" math
  a + b, a - b, a * b, a / b
* Object types have their own methods (add, multiply, etc.)

Integer i = new Integer(10);
cannot write
BigInteger bi = new BigInteger(10);
instead write
BigInteger bi = BigInteger.valueOf(10);

To print the largest Integer
	pen.print("The largest integer is ");
	pen.println(Integer.MAX_VALUE);
To add 1 to the largest short
	short s = Short.MAX_VALUE;
	s = s + 1;
	pen.println(s);