Java   View all facts   Glossary   Help

syntactic unit > access unit > variable > variable declared as a non-primitive data type > variable whose type is an abstract class

variable whose type is an abstract class
subject			fact

variable whose type is an abstract class	contains an instance of any subclass of the abstract class
	is a subtopic of Variables and Data Types
	is a kind of variable declared as a non-primitive data type
variable declared as a non-primitive data type	is used by calling methods or accessing the object's instance variables
	refers indirectly to its value which is an object
	uses the name of a class as its type
variable	can be accessed by other variables and methods in any class in the same package by default
	can have an interface as its type which means that, with the variable, you can invoke any operation supported by the interface
	can refer to a particular object, several different objects during the execution of a program, or no object at all
	has 1 value at any one time which is the object or class or primitive datum that it refers to
	has 1 name
	has scope which is the block in which it is declared
	has type
	has lifetime which is the time its block is being executed
	has purpose to refer to an object or a class or a primitive datum
	has scope
	has part value
	is declared by giving the data type followed by the name of the variable
	is destroyed in the block where it is declared
	may have access modifier public or private or protected
	refers to a class or an object or a primitive datum
	should be as private as possible
	should have comment if it is non-obvious
access unit	has access mode
syntactic unit	has syntax rule bold = mandatory italic = non-terminal normal font = optional

Up: variable declared as a non-primitive data type