Wrapper Classes in Java
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Wrapper classes allow primitive data types to be treated as objects.
Each primitive type has a corresponding wrapper class:
- int → Integer
- double → Double
- char → Character
- boolean → Boolean
Wrapper classes are mainly used in:
- Collections like ArrayList
- Utility methods
- Object based operations
Integer
Integer provides useful methods like parseInt(), toString(), compareTo().Double
Wrapper classes contain conversion and utility methods.
Character
Boolean
Autoboxing
Autoboxing is automatic conversion of primitive type to wrapper object.
Java automatically converts int to Integer.
Unboxing
Unboxing is converting wrapper object back to primitive type.
Java automatically converts Integer to int.