LECTURE NOTES
OCTOBER 4 2004

ANNOUNCEMENTS
First Midterm Exam

  Regular Time
  Tuesday October 5 5:00-7:00 pm
  1227 Engr Hall
  Different proctor

  Alternate Time (prearranged)
  Tuesday October 5 7:00-9:00 pm
  1221 CSS
  I will proctor

  Bring several #2 pencils and your UW student ID

Review Session
  Today 6-9 pm
  CSS 1325

ASSIGNMENTS
Fri 10/8 11:58 PM CodeLab #5

MORE ARITHMETIC OPERATORS

Why?
- adding one to something is very common
What?
- increment operator
How?
  <variable name>++;

Why?
- subtracting one from something is very common
What?
- decrement operator
How?
  <variable name>--;

BOOLEAN EXPRESSIONS

What?
- boolean values
How?
- true/false
- reserved words

Why?
- generate booleans from other data
What?
- *relational operator*
How?
<
<=
==
!=
>
>=

What?
- comparing reference types
How?
- using == only compares values directly: whether or not they point to the same address
- writing comparison methods in classes to compare object data members

What?
- String comparison methods
How?
- equals
- equalsIgnoreCase

What?
- *boolean expression*

What?
- *boolean operator*
- *logical operator*
How?
&&
||
!

What?
- reversing relational operators
- DeMorgan's Law
How?
- change the sign and the presence of the =
- negate the boolean expression

Why?
- recognizing run-time errors
What?
- *short-circuit evaluation*
How?
- e.g. *divide-by-zero error*

Why?
- avoid short circuiting
- not used in this course
How?
| and & operators