Differences between basic types and packaging classes

    difference ：

    1. Basic types are stored on the stack , The package type is stored in the stack . Because the stack is more efficient , So the basic types are preserved .

    2. The packaging class is the object , Have methods and fields , The invocation of an object is the address of the reference object .

    3. The basic type is value passing , Wrapper classes are reference passing .

    4. towards ArrayList,LinkedList When releasing data , You can only put Object Type of , The basic type cannot be put in .

    Basic types , Packaging And its default value , The default value for the wrapper class is Null.

    byte         0            Byte            

    short        0            Short

    int            0            Integer         

    long        0             Long

    float        0.0          Float

    double    0.0          Double

    char        Space         Character

    boolean    false       Boolean