Java Road Static

1 /*2 static (statically)3 4 Requirement: Describe the class of the student of wisdom. It's all Chinese ....5 6 7 existing problems: All students are Chinese, there are n students will have n copies of China's data in memory, so that the child8 will waste memory. 9 Ten Current Program: The "China" this data to the data sharing area, sharing this data for all student objects to use.  One  A Question 2: How can I move this data to a data share?  -  - solution: Just use static to decorate the data.  the  -  - static member variables maintain only one copy in the data share, and the data for non-static member variables is maintained in one copy of each object.  -  + */ -  + classstudent{ A  at String name; -      -     //with the static modifier country, then country is a shared data.  -  -     StaticString country = "China";//Nationality -      in     //constructor Function -      PublicStudent (String name) { to          This. Name =name; +     } - } the  * classDemo9 { $ Panax Notoginseng      Public Static voidMain (string[] args) -     { theStudent S1 =NewStudent ("Zhang San"); +Student s2 =NewStudent ("Chen Qi"); A  theS1.country = "Little Japan"; +System.out.println ("Name:" +s1.name+ "Nationality:" + s1.country);//China -System.out.println ("Name:" +s2.name+ "Nationality:" + s2.country);//Little Japan $     } $}

1 /*2 static \ Modifier3 4 1. Static modifier member Variable: You can use the static modifier if there is data that needs to be shared with all objects. 5         6 how static member variables are accessed:7                 8 Mode 1: You can use objects for access. 9 format: Object. Variable name. Ten                  One method Two: You can use the class name for access.  A format: class name. variable name; -      - Note: the 1. Non-static member variables can only be accessed using an object and cannot be accessed using the class name.  - 2. Do not use static modifier member variables for easy access to data, only when data for member variables is really needed to be shared - before using the static modifier.  -              + static Modify the application scenario for member variables: If a data needs to be shared by all objects, this is a good time to use static adornments.  -  +  A 2. Static modifier member function: at  - */ -  - classstudent{ -  -     StaticString name;//non-static member variable in      -     StaticString country = "China";//Static member variables to      +      PublicStudent (String name) { -          This. Name =name; the     } * } $ Panax Notoginseng  - classDemo10 { the  +  A      Public Static voidMain (string[] args) the     { +Student S1 =NewStudent ("Dog Doll")); -Student s2 =NewStudent ("The Dog left"); $          $         //System.out.println ("Nationality:" + student.country); -System.out.println ("Name:" +s1.name); -System.out.println ("Name:" +s2.name); the     } -}

Java Road Static