Wrapper classes:
- Collection stores only objects (not primitive data).
- Wrapper classes providing functionality to perform conversions like
- Primitive -> Object (Boxing)
- Object -> Primitive (Un boxing)
- These conversions become automated since JDK5
Note: for every primitive type there is a wrapper class in java
| Primitive type | Wrapper class |
| byte | Byte |
| short | Short |
| int | Integer |
| long | Long |
| char | Character |
| float | Float |
| double | Double |
| boolean | Boolean |
Boxing: Conversion of primitive type into object type
| int x = 10; Integer obj = new Integer(x); |
Un boxing: Conversion of object type into primitive type
| int x = obj.intValue(); |
Auto Boxing: Auto conversion of boxing
| int x = 10; Integer obj = x; |
Auto Un boxing: Auto conversion process of un boxing.
| int x = obj; |