WrClasses-WE3-P1

Section 10.7 WrClasses-WE3-P1

Subgoals for Writing a Class.

Name it
Differentiate class-level static vs. instance/object-level variables
Differentiate class-level static vs. instance/object behaviors/methods
Define instance variables (that you want to be interrelated)
1. Name
2. Data Type
3. private
Define class variables static as needed
1. Name
2. Data Type
3. public / private / final
Create constructor (behavior) that creates initial state of object
1. Overloaded constructor (with as many parameters)
2. public
3. Same name as class
4. No return type
5. Default - no parameters
6. Logic - initialize all variables
7. Repeat as needed, adding parameters
Create 1 accessor and 1 mutator behaviors per attribute
1. Accessors
  1. Name is get_<attr_name>
  2. Public
  3. Return type same data type as attribute
  4. No parameters
  5. Logic - return value
2. Mutators
  1. Name is set_<attr_name>
  2. Public
  3. Return type is void
  4. Parameter is same data type as attribute
  5. Logic validates input parameter and sets attribute value
Write toString method
1. public
2. Returns String
3. No parameters
4. Logic - convert needed attributes to a format that can be printed
Write equals method
1. public
2. Returns boolean
3. Parameter - instance of the class
4. Logic - compare attributes for equity
Create additional methods as needed

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Subsection 10.7.1 Classes-WE3-P1

Consider the SongType class you began in an earlier exercise, as illustrated in the following UML diagram.

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Fill in the blanks for the following code:

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public class SongType {
   //attributes declared here
   //...

   //getters/accessors
   public ___A___ getTitle () {
      ___B___ ___C___;
   }
   ___D___ String ___E___ () {
      ___F___ artist;
   }
   public ___G___ getLength () {
      ___H___ ___I___;
   }

   //setters/mutators
   public ___J___ setTitle (String n) {
      title = ___K___;
   }
   ___L___ void setArtist (___M___ n) {
      artist = ___N___;
   }
   public ___O___ setLength (___P___ n) {
      if (n > 0)
         ___Q___ = n;
   }
}