LECTURE
OCTOBER 27 2004

ASSIGNMENTS
Today 6:00 PM Assignment 3 Design
Fri 10/29 CodeLab #8

COMPARING STRINGS

What?
- compareTo method
How?
- String instance method
- argument: another String
- returns an int
  - 0 if they are equal
  - a negative number if the argument is less than the instance
  - a positive number if the argument is greater than the instance
  - the exact numerical value depends on the relative Unicode lexicographic order

STRING MANIPULATION

What?
- immutability of Strings
How?
- none of our methods can directly alter a string object
Why?
- makes memory allocation more efficient
- lets us treat Strings as primitives

What?
- *string manipulation*
How?
- In Java, StringBuffer class
- can directly alter the value of a StringBuffer

What?
- creating new instances of StringBuffer
How?
- must explicitly use the reserved word new
- constructor takes a single String argument
- changes do not affect original constructor argument

What?
- setCharAt method
How?
- StringBuffer instance method
- first argument: int character position
- second argument: char new value of that position

What?
- append method
How?
- StringBuffer instance method
- argument: any primitive
- concatenates the argument to the StringBuffer

What?
- append versus concatenation
How?
- may be used implicitly by the compiler for concatenation
- more efficient than concatenation because avoids creating temporary variables