What are wrapper classes
A wrapper class is nothing but primitive wrapper class in Java is one of eight classes provided in the java.lang package which are imported by default into all Java programs. All of the primitive wrapper classes in Java are immutable.
JDK 5 introduced autoboxing of primitive types into their wrapper class object, and automatic unboxing of the wrapper objects into their primitive value the implicit conversion between the wrapper objects and primitive values.
The primitive wrapper classes and their corresponding primitive types are shown below:
| Wrapper class | Primitive type | Constructor arguments |
| byte | Byte | byte or String |
| short | Short | short or String |
| int | Integer | int or String |
| long | Long | long or String |
| float | Float | float, double or String |
| double | Double | double or String |
| char | Character | char |
| boolean | Boolean | boolean or String |
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