Create a class
more than a angle brackets, capital letters E, What does it mean?
Angle brackets which is called generics. Unified type of storage, the type and wrote in angle brackets which we expressed in a letter placeholder.
How to create it constructor has three, the most common is no argument constructor
first master the add method inside of
generics can only be a reference type, not a basic type
must be written within angle brackets on the left and right can write you can not write
print out not an address
to write to this person ArrayList ArrayList has been specially
entered, the error will add digital
Ctrl + left mouse button you can also enter the source code inside ArrayList
