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uninitialized object
subjectfact 
uninitialized objecthas definition An object that has been declared but has not been assigned a valuesource: Object Oriented Software Engineering by Lethbridge and Laganière, 2001-10-19 11:38:11.0
has value null    source: Object Oriented Software Engineering by Lethbridge and Laganière, 2001-10-19 11:38:11.0
is a subtopic of Objects2001-10-19 11:38:11.0
is a kind of objectsource: Object Oriented Software Engineering by Lethbridge and Laganière, 2001-10-19 11:38:11.0
object
when an object is created
  1. the object's variables are set to default values
  2. the constructor of the object's superclass is invoked
  3. the object's initialization block is invoked
  4. the object's constructor is invoked
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  • when an object is not needed any longer
  • the object's space is garbage collected
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can access all instance variables of all objects of its class2001-10-19 11:37:31.0
can be encapsulated by providing accessor methods2001-10-19 11:37:31.0
can be converted into a string using the toString method    2001-10-19 11:37:31.0
can be referred to without reference to the instance variables contained in it    2001-10-19 11:37:31.0
can be referred to by several different variables at the same time    2001-10-19 11:37:31.0
can communicate with every object to which it has access through its public interface2001-10-19 11:37:31.0
can convert itself to a string representation using the toString method    2001-10-19 11:37:31.0
can model    2001-10-19 11:37:32.0
can notify other objects that a condition variable has changed2001-10-19 11:37:32.0
can receive messages from    2001-10-19 11:37:32.0
can represent any entity to which you can associate properties and behaviour    2001-10-19 11:37:32.0
can return its class using the getClass method2001-10-19 11:37:32.0
can send messages to    2001-10-19 11:37:32.0
can wait on 0 or more condition variables2001-10-19 11:37:32.0
communicates with other objects by sending and receiving messages    2001-10-19 11:37:32.0
has 0 or more instance variables2001-10-19 11:37:32.0
has 0 or more methods called instance methods2001-10-19 11:37:32.0
has behaviour that is specified by its methods    2001-10-19 11:37:32.0
has state that is maintained in its variables    2001-10-19 11:37:32.0
has example of creation String name = new String();2001-10-19 11:37:32.0
has part public interface2001-10-19 11:37:32.0
hides methods from other objects using the 'private' keyword2001-10-19 11:37:32.0
inherits instance methods and instance variables from
  • the class to which it belongs
  • all that class's superclasses
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is distinct from every other object even if they contain the same data    2001-10-19 11:37:32.0
is created by
  • declaring and initializing it such that it is created whenever execution enters a particular block, or, in the case of an instance variable, when an instance is created, for example:
    String aString = "some text";
  • or by declaring it and initializing it later using the new operator, for example:
    String aString;
    aString = new String("some text");
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shares every instance method of its class with the other instances of its class2001-10-19 11:37:32.0
shares its implementation with other instances of its class2001-10-19 11:37:32.0
shares one copy of each class variable of its class with the other instances of its class    2001-10-19 11:37:32.0
to create you use the new operator2001-10-19 11:37:33.0

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