Primitive wrapper class in Java: Difference between revisions

Revision as of 08:31, 8 August 2022

Revision as of 21:26, 10 December 2022

Line 1:

In [[object-oriented programming]], a '''wrapper class''' is a [[class (computer programming)|class]] that [[Encapsulation (computer programming)|encapsulates]] [[data type|types]], so that those types can be used to create [[object (computer science)|object]] [[instance (computer science)|instances]] and [[method (computer programming)|methods]] in another class that needneeds those types. So a '''primitive wrapper class''' is a wrapper class that encapsulates, hides or ''wraps'' data types from the eight [[primitive data type]]s,<ref>S. J. Chapman, ''Introduction to Java'', Prentice Hall, 1999.</ref> so that these can be used to create instantiated objects with methods in another class or in other classes.<ref name=murach>J. Murach, ''Murach's Java Programming'', 4th Edition, Mike Murach and Associates, Inc., 2011.</ref><ref>J. R. Hubbard, ''Programming with Java'', Schaum's Outline Series/McGraw Hill, 1998.</ref> The primitive wrapper classes are found in the [[Java API]].

Primitive wrapper classes are used to create an {{Javadoc:SE|java/lang|Object}} that needs to represent primitive types in {{Javadoc:SE|java/util|Collection}} classes (i.e., in the Java API), in the {{Javadoc:SE|package=java.util|java/util}} package and in the {{Javadoc:SE|package=java.lang.reflect|java/lang/reflect}} [[Reflection (computer science)|reflection]] package. Collection classes are Java API-defined classes that can store objects in a manner similar to how data structures like arrays store primitive data types like '''int''', '''double''', '''long''' or '''char''', etc.,<ref name=murach/> but arrays store primitive data types while collections actually store objects.