Java All objects packaging, automatic packing, automatic unpacking

Each basic type has a corresponding class, which is the so-called wrapper class;

1, crating and unpacking

Basic types and class types can be converted to each other;

The conversion of the base type to the class type is called boxing;

The conversion of a class type to a basic type is called unpacking;

2, automatic box packing and unpacking

In the conversion of class type and base type, it is automatic conversion without forcing type conversion;

3, the role of packaging class

Here is the function of the wrapper class, because the wrapper class is the class type all JDK provides a lot of useful methods for us to use;

For example, from the user interface to two string data, a, and then our program to do the addition operation. This is where the packing class comes in handy,

We can use the wrapper class's method class for type conversion. Let's look at the sample code:

Java All objects packaging, automatic packing, automatic unpacking