A Wrapper class is a class whose object wraps or contains a primitive data types. When we create an object to a wrapper class, it contains a field and in this field, we can store a primitive data types.
In other words, we can wrap a primitive value into a wrapper class object.
Need of Wrapper Classes
- They convert primitive data types into objects. Objects are needed if we wish to modify the arguments passed into a method (because primitive types are passed by value).
- The classes in java.util package handles only objects and hence wrapper classes help in this case
- Data structures in the Collection framework, such as ArrayList and Vector, store only objects (reference types) and not primitive
- An object is needed to support synchronization in multithreading.
Wrapping & Unwrapping Example