Java Autoboxing: Difference between revisions
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Java has a mechanism called ''boxing'' that converts primitive types (such as <tt>int</tt>) into their corresponding reference types (<tt>java.lang.Integer</tt>). The opposite operation, converting reference types into their corresponding primitive types is called ''unboxing''. | Java has a mechanism called ''boxing'' that converts primitive types (such as <tt>int</tt>) into their corresponding reference types (<tt>java.lang.Integer</tt>). The opposite operation, converting reference types into their corresponding primitive types is called ''unboxing''. | ||
''Autoboxing'' is a mechanism that performs boxing and unboxing automatically. | ''Autoboxing'' is a mechanism that performs boxing and unboxing automatically. | ||
Autoboxing comes with a performance cost. Boxed values are wrappers around primitive types, and are stored on the heap. Therefore, boxed values use more memory and requires additional memory lookups to fetch the wrapped primitive type. | |||
=TODO= | =TODO= | ||
* https://docs.oracle.com/javase/tutorial/java/data/autoboxing.html | * https://docs.oracle.com/javase/tutorial/java/data/autoboxing.html | ||
Revision as of 20:39, 23 March 2018
Internal
Overview
Java has a mechanism called boxing that converts primitive types (such as int) into their corresponding reference types (java.lang.Integer). The opposite operation, converting reference types into their corresponding primitive types is called unboxing.
Autoboxing is a mechanism that performs boxing and unboxing automatically.
Autoboxing comes with a performance cost. Boxed values are wrappers around primitive types, and are stored on the heap. Therefore, boxed values use more memory and requires additional memory lookups to fetch the wrapped primitive type.