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member > instance member > instance variable |
instance variable (data member, field, object variable) | ||||
subject | fact |
instance variable | is a synonym of data member | |
is a synonym of field | ||
can be inherited | ||
can be accessed by all methods of its class | ||
can be made private to prevent direct access to instance variable - accessor methods should be used instead to protect data abstraction | ||
has definition A data item present in all the instances of a class, normally used to implement associations and attributes | ||
has definition Any item of data that is associated with a particular object. | ||
implements an attribute or an association | ||
is part of an object | ||
is a subtopic of Members | ||
is defined by an instance variable definition | ||
is a kind of instance member | ||
is a kind of member variable | ||
maintains part of its object's state | ||
refers to an object or a primitive | ||
should be as private as reasonably possible - almost never make an instance variable public | ||
should be placed in a class such that there is no needless duplication of it, and such that it is useful in all the subclasses of the class in which it is defined | ||
to refer you join the name of the variable with a dot to the instance variable name. Example: variableName.instanceVariableName | ||
is a synonym of object variable | ||
member variable | can be declared anywhere in a class outside of a method | |
can be initialized by an assignment statement | ||
is a member of a class or an object | ||
is accessible to the code in its class | ||
variable | can contain different classes of objects depending on the type of the variable | |
can contain only values that are of the same type as the variable or a subtype of the variable's type | ||
can have an interface as its type which means that, with the variable, you can invoke any operation supported by the interface | ||
has 1 value at any one time which is the 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 | ||
should have comment if it is non-obvious | ||
access unit | has access mode | |
syntactic unit | has syntax rule bold = mandatory |
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