[자바 기술면접] 16. 기본 데이터 유형 vs 참조 데이터 유형

- 정의  

기본 데이터 유형 : 언어 자체에서 제공하는 기본적인 데이터 유형.

참조 데이터 유형 : 클래스나 인터페이스를 사용하여 생성된 객체.

 

 - 종류 

기본 데이터 유형 : byte, short, int, long, float, double, char, boolean

참조 데이터 유형 : Byte, Short, Integer, Long, Float, Double, Character, Boolean (래퍼 클래스)

 

- 메모리 할당 방식

기본 데이터 유형 : 스택 메모리 영역에 직접 값을 저장

참조 데이터 유형 : 힙 메모리 영역에 객체 생성 후 스택 메모리에 래퍼 클래스 객체의 주소만 저장

 

- 영어 정리 : 

Primitive data types are basic data types provided by Java, such as int, char, boolean, double, float, byte, short, and long. These data types are stored in the stack memory, which is a temporary memory space used to store variables that are created inside a method or a block of code. Stack memory is managed automatically by Java, and the variables stored in it are removed as soon as the method or block of code is executed.

Wrapper classes, on the other hand, are classes that encapsulate primitive data types in objects. They include Integer, Character, Boolean, Double, Float, Byte, Short, and Long. Wrapper classes are used to represent primitive data types as objects, which allows them to be used in situations where objects are required. Wrapper objects are stored in the heap memory, which is a permanent memory space used to store objects and their data. The heap memory is managed by the Java Virtual Machine (JVM), and it is not automatically cleared like the stack memory. Instead, it is cleared by the garbage collector, which runs periodically to remove objects that are no longer in use.