20165208 2017-2018-2 "Java Programming" Seventh Week study summary

20165208 2017-2018-2 "Java Program design" Seventh Week study summary textbook Study content summary 11th Chapter

Preparatory work: Installation of XAMPP

Creating a database table

Query modify and update tables in the database

Focus: Using Preprocessing statements

Problems in code debugging and the resolution process

Issue one: A problem occurred at run time the public class needs to be declared. Specific

Solution One: Fixed a few places can not run successfully, and later found that the first file name is not consistent with the main class name, modified to run correctly

Code Hosting

Last week's summary of the wrong quiz

Item A: If the specified object cannot be compared with the current element in the set, the ClassCastException exception is thrown.

C: An object variable holds a reference. D: Output is the entity of the object.

Out.println (S1 = = s2);//① "= =" usage. S1 and S2 are not an object, false.

Out.println (s1.equals (S2));//② "equals" usage. S1 is the same value as S2, true.

Out.println (S1.matches (S3));//③ "matches" usage. S1 conforms to the regular expression s3,true.

Out.println (S1.contains (S3));//④ "contains" usage. S1 does not contain the contents of S2, false.

Out.println (S1.contains (S4));//⑤ "contains" usage. S4 is a substring of S1, true.

D: If you want to print an array, the array must call the static method arrays.tostring, that is, string S1 = "" +numbers in the above program; change to string S1 = arrays.tostring (Numbers);. If you want to print a multidimensional array, you need to call the Arrays.deeptostring method.

B: The finally code block defines code that is bound to execute, which is typically used to close a resource. For the exception of the part, if not done finally, then the program is flawed, each call to the resources and then release the resources is necessary, otherwise the operating pressure will be particularly large.

Resources

• "Java2 Practical Course (Fifth Edition)" Learning Guide
• "Intellj Idea Simple Tutorial" learning Guide

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	36/36	4/4	30/30
Second week	464/500	1/5	18/48
Third week	832/1332	2/7	17/65
Week Four	939/2271	2/9	17/65
Week Five	1163/3434	1/10	17/65
Week Six	1176/4610	1/11	15/65
Seventh Week	864/5474	2/12	15/80

20165208 2017-2018-2 "Java Programming" Seventh Week study summary