201671010128 2017-10-08 "Java programming" lambda and internal classes

First, the basic concept

1. Java LAMBDA expressions are a new feature introduced in Java 8, and the main purpose is to provide a functional syntax to simplify coding.
2. A lambda expression is essentially an anonymous method.
3. Java LAMBDA Expressions use the functional interface as the base of the application.
4. An inner class (inner class) is a class that is defined inside another class.

Ii. Points of attention

• There are three reasons for using internal classes:

1. An inner class method can access the data in the scope where the class definition resides, including private data.
2. Inner classes can be hidden and not seen by other classes in the same package.
3. Using anonymous inner classes is convenient when you want to define a callback function and do not want to write a lot of code.

• An inner class object holds a reference to an external class object that, when a variable is accessed in the member method of the inner class, is not defined in the method and inner class, and the reference to the variable in the inner class is passed to the reference of the outer object.

Third, object-oriented program design course study progress bar

Week	(read/write) Number of lines in code	Post Blog volume/comment blog number	classroom/After School time (hours)	Most satisfying programming task
first week	20/7	1/1	6/4	write Hello World program
second week	38/20	1/1	6/5	Experiment two tasks three
third week	50/30	1/1	6/7	experiment three
Fourth week	58/46	1/1	6/5	Edit Write output n digits number, and sum
Fifth week	67/53	1/1	6/6	class definition and overloading
Sixth week	71/60	1/1	6/4	interface
Eighth Week	80/66	1/	6/3	lamdba expression
...
Cumulative	384/275	7/6	42/34

201671010128 2017-10-08 "Java programming" lambda and inner class