Reading
Chapter 4
Section 5

- mutator: a method that changes a property of an object
- usually a single property is maintained by a single data member
- how a property of an object is represented inside the object
  - internal detail
  - does not concern the client programmers
- accessor: method that returns a property of an object
- common practice to define mutators and accessors in pairs
- naming multiple methods with the same name just like constructors
  - allowed
  - rules
    - must have a different number of parameters OR
    - parameters must have different data types
- overloaded method: method that has the same name as another method in the class
- duplicating code
  - avoid whenever possible
  - makes modification of code tedious and error-prone because must locate all places where changes made
- calling a method from a method of the same object
  - allowed
  - dot notation
    - allowed
    - not required
    - use in conjunction with the reserved word this
    - more common not to use
  - calling methods within constructors
    - allowed
    - instance not created until a constructor complete execution
    - rules
      - if used, the call to a different constructor must be the first line
      - instance methods may not be used as arguments a different constructor
- important to test other
  - all constructors and methods with different values for arguments
  - different combinations of mutators and accessors

Quick Check
1.  class One {
        private int var1;
        private int var2;

        public m1() {
            this.var1 = 20;
            this.m2(this.var1);
        }

        public m2(int x) {
            this.var2 = x * 2;
        }
    }
2.  It involves code duplication.  It could use other methods, already defined, which apply these formulas.  That would prevent the same formulas from appearing in multiple places.