Reading
Chapter 4
Section 4

- only covers primitives
- data members of a class are accessible from all instance methods of the class
- how local variables are declared
  - local variable: variable declared within the method declaration
    - used for temporary purposes
    - store intermediate results of a computation
  - local variables and parameters
    - accessible only from the method in which they are declared
    - available only while the method is being executed
    - memory space
      - allocated at the beginning of the method
      - erased upon exiting from the method
- how arguments are passed to a method
  - value of argument passed to parameter in same position in the list
  - passing occurs when method is called
  - pass-by-value: 
    - also call-by-value
    - new memory space is allocated for the parameter
    - parameter
      - gets a copy of the argument
      - is local to the method
    - changes made to the parameter do not affect the original argument
  - data type of argument must be assignment-compatible with the data type of the matching parameter
  - parameter and argument names can be the same
  - program diagram notation
    <visibility symbol> <method name>(<list of paramter types>)
- how values are returned to a method
  - data type of the value returned must be assignment-compatible with the declared return type of the method
  - a call to a method with a return type can be used as an expression
  - method composition
    - definition: passing the returned value of a method as an argument to another method
    - allowed
  - program diagram notation
    <visibility symbol> <method name>(<list of parameter types>) : <return type>
    - also use colon notation to designate data member data types
      <visibility symbol> <data member name> : <data type>
- differentiating data members from local variables and parameters
  - using the same name for data members and parameters or local variables
    - valid
    - not usually recommended
  - local variable and parameter can never have the same identifier because they are both declared locally
  - rules for associating an indentifier with a value
    - if there's a matching local variable declaration or parameter, resolve the identifier to this
    - otherwise, if there's a matching data member, resolve the identifier to this
    - otherwise
      - there is no such data
      - compiler error
  - may wish to use an identifier for both a data member and a parameter when setting the data member
  - use this.<identifier> to refer to a data member
    - this is a reserved word
    - called dot notation
    - if no local variable or parameter was declared using the same identifier
      - can still be used
      - need not be used
    - common practice not to use unless necessary
  - avoid naming conflict and use meaningful name by prefixing an article
  - technique for avoiding a naming conflict is a personal choice

Quick Check:
1. local variables: two, three
   parameters: one
   data members: one, four
2. the method returns a value and is also declared void
3. methodTwo and methodThree are private
4. public Test (double score) {
       this.score = score;
   }