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A primitive - wrapper class in the Java and ActionScript programming languages is one of eight classes provided in the package to provide object methods for the eight primitive types. All of the primitive wrapper classes in Java are immutable. J2SE 5.0 introduced autoboxing of primitive types into their wrapper object, and automatic unboxing of the wrapper objects into their primitive value—the implicit conversion between the wrapper objects and primitive values. Wrapper classes are used to represent primitive values when an is required. The wrapper classes are used extensively with classes in the package and with the classes in the reflection package. The primitive wrapper classes and their corresponding primitive types are: : Don't get confused The term mentioned ''Primitive Wrapper Classes'' does not really mean that Wrapper classes are Primitive types in Java. It should be read this way, a class that wraps a primitive type. Wrapper classes can be used to store the same value as of a primitive type variable but the instances/objects of wrapper classes themselves are ''Non-Primitive''. We cannot say that Wrapper classes themselves are Primitive types. They just wrap the primitive types. The Byte, Short, Integer, Long, Float, and Double wrapper classes are all subclasses of the class.The wrapper classes BigDecimal and BigInteger are not one of the primitive wrapper classes but are immutable.〔(【引用サイトリンク】 title = Java documentation from oracle )〕 == Void == Although it is a wrapper class, the class is similar in that it provides an object representation of the void return. "The Void class is an uninstantiable placeholder class used by the API to hold a reference to the object representing the Java keyword void."((Javadoc for Void) )抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Primitive wrapper class」の詳細全文を読む スポンサード リンク
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