Java Lecture Notes - 2012.02.16

 

Example)

     class Box {   // class Box individually storing case! : classbefore public enter,
          int width;

          int height;

          int depth;

     }

+ constructor without case, 
          JVM default constructor creates.

                super() basic included 

                width=0;

                height=0;

                depth=0;
           creates.

mybox1 = new Box(); //memory structure
                heapon definition memory space that memory space refers to separate's name none 

                only stackon's reference variable addressvalues having only.

 

[public/private] [static/final] variabletype(data type) variable;
 

          >membervariable

                1.objectvariable (static final attached not variable)

                2.static : class variable

                3.finalvariable : terminal variable, "readingonlyvariable" 

                                 = inheritance(classfrom),re-definition(methodfrom), blockfor attribute

 

>inheritancerelationship
     Package   default       inheritanceclass o   internalclass x
                     public        inheritanceclass o   internalclass o

                     private      inheritanceclass x   internalclass x

                     protected  inheritanceclass 0  internalclass x

     external
     Package   default        class x        inheritanceclass x     

                     public         class o        inheritanceclass o 

                     private       class x        inheritanceclass x 

                     protected   class x        inheritanceclass o 

object reference variable 
     : object for address copyis pass eventually same object point to
ex)
      Box mybox1 = new Box();

      Box mybox2 = mybox1;

      value not addressonly passing .

 

class variable(static data member) static attaching declaration
           newoperation object only previous definition.

           destruction : program when ending

           however memory =“this.” re- neededX.

           all object class variable

           objectvariableand class variable class name by access

 

constructor(Constructor)
           constructor name class name equal (character to occurrence)

           Resulttype re- cannot. (void even .) =retun usage not possible

 

constructor overloading(Overloading)
           this(value) ; form same class other constructor auto call

           execution can. (constructor first of must compose)

 

""  = string String object auto store (argumentpass= reference )

 
 

this ...(.. or needed)
      1.position

      2.refers to(localsamewhen)
      3.same not other constructor call needed when 
             = (3among usage 1or2 or3among only input case 

             programon default values specifymainfor)