20165237 2017-2018-2 "Java Programming" 2nd Week study Summary

20165237 2017-2018-2 "Java Program Design" 2nd week study summary Textbook study summary

1. The first character of an identifier cannot be a number.

2. Identifiers cannot be keywords and cannot be true, FALSE, or null.

3. The logical type of Boolean has true and false two cases.

4. Data precision ranking from large to small:
Double>float>long (8 bytes) >int (4 bytes) >char>short (2 bytes) >byte (1 bytes).

5. After the int number is greater than the byte tolerance range, the modulo 128 operation is performed.

6. Create an object using the Scanner class Scanner reader = new Scanner (system.in); The Reader.next data type () invokes the various basic data types entered by the command line. Reader.nextint () is waiting for the input cursor.

The difference between 7.system.out.println and System.out.print is that the former outputs data and wraps, and the latter does not break the line. You can also use + to output a variable expression or a constant value with a string. (println comes with "/n").

8. Declare an array: int a[] or int []a.

9. Create an array: a = new int (type) n number of elements.

10. The length of the array, A,length = N, is the number of elements of array A.

11. Operators and expressions are similar to C-language use

Code Hosting

(run result of statistics.sh script)

This week's Code project

Other (sentiment, thinking, etc., optional)

This week's knowledge made me and C language content together, found that particularly good understanding, just changed a framework. You have to keep trying!

Learning progress Bar

	lines of code (new/cumulative)	Blog Volume (Add/accumulate)	Learning Time (new/cumulative)	Important Growth
Goal	5000 rows	30 Articles	400 hours
First week	80/80	1/1	18/18	Learn to write simple Java applications
Second week	357/437	2/3	15/33	Mastering the use of arrays, symbols, and data

20165237 2017-2018-2 "Java Programming" 2nd Week study Summary