abcd blocks

1. Static initialization block　　Static initialization blocks are only executed once when the class is first loaded , while static initialization blocks can only assign values to static variables and cannot be assigned to normal member variables.2. (non-static) initialization block　(non-static) initialization blocks are executed once each time the instance object

. Access class variables through any instance of the class, and the underlying will turn them into class variables through the class itself, with the same effect 5. Once the value of the class variable is changed, the class variable is accessed through any instance of the class or class, and the resulting value is changed. 6. The class will be initialized before the initialization of the instance variable (non-static variable) 1. Cannot forward reference, if forward reference, is called illegal

In Java and Android, what is the difference between the execution order of blocks of code and static code blocks?JavaLet's start with a simple example.Main.java:publicclass Main { staticint1; static { System.out.println(a); } static { 2; } publicstaticvoidmain(String[] args) { System.out.println("Hello World!"); System.out.println(a); }}Output to 1He

Building blocks: Code blocks that are written directly in a classStatic code collapse: blocks of code declared with the static keywordStatic code blocks are constructed before the construction block, and are executed only once when the class is loaded, and later when the class is instantiated, the building

Transferred from: http://www.cnblogs.com/sophine/p/3531282.htmlCommon code blocks in Java, building blocks of code, static code block differences, and code examplesExecution order: (Priority from high to low.) Static code block >mian method > construct code block > Construct method.Where static code blocks are executed only once. The construction code block execu

Execution order: (Priority from high to low.) Static code block >mian method > construct code block > Construct method.Where static code blocks are executed only once. The construction code block executes every time the object is created.1 Common code blocks1//Common code block: {} that appears in a method or statement is called a normal code block. Ordinary blocks of code and general execution order of sta

Execution order: (Priority from high to low.) Static code block >mian method > construct code block > Construct method.Where static code blocks are executed only once. The construction code block executes every time the object is created.1 Common code blocks1//Common code block: {} that appears in a method or statement is called a normal code block. Ordinary blocks of code and general execution order of sta

1 Public classSTR {2 3 Static {4System.out.println ("Static{1}");5 }6 Static {7System.out.println ("Static{2}");8 }9 {TenSystem.out.println ("{}"); One } A - Str () { -System.out.println ("Str ()"); the } - - Public Static voidMain (string[] args) { - NewStr (); + NewStr (); - } +}Output Result:Static{1}STATIC{2}{}STR (){}STR ()Conclusion:1. Static code blocks are executed sequentially and execut

Execution order: (Priority from high to low.) Static code block >mian method > construct code block > Construct method.Where static code blocks are executed only once. The construction code block executes every time the object is created.1 Common code blocksOrdinary code block: {} that appears in a method or statement is called a normal code block. Ordinary blocks of code and general execution order of stat

Oracle tablespaces (tableSpace), segments (segment), disk partitions (extent), and blocks are all allocated unit segments used by Oracle to save database objects. Oracle tablespaces (tableSpace), segments (segment), disk partitions (extent), and blocks are all allocated unit segments used by Oracle to save database objects. OracleTablespace (TableSpace), Segment (Segment), Disk Area (Extent), Block (Bl

In a recent review of some of the knowledge in Java, here is a way to learn about static blocks of code and construct blocks of code.First of all, the code is balabala some definitions Ah, assignment Ah, the operation of some Java code, surrounded by two curly braces, it becomes a magic block of code{ a=3;} static{ b=4;}Just like the one above.The parentheses add static to the code block, you

Before starting this blog writing, please look at a classic Java face questionpublic class statictest{ public static void Main (String args[]) { Staticfunction (); } static Statictest st = new Statictest (); static{ System.out.println ("1"); } Statictest () { System.out.println ("3"); System.out.println ("a=" +a+ "b=" +b); } public static void Staticfunction () { System.out.println ("4"); } { System.out.println ("2"); }

Java static code blocks, construction code blocks, execution order of construction methodsstatic code takes precedence over non-static code because members that are modified by static are members of a class and are executed as the JVM loads the class, while members that are not statically decorated are also called instance members, and need to create objects to be loaded into heap memory. So static will tak

BBED marks Bad blocks and fixes bad blocks. Create a test table: ZBDBA@orcl11g>select * from zbdba;NAME------------------------------------------------------------zbdbahuihuiZBDBA@orcl11g>ZBDBA@orcl11g>ZBDBA@orcl11g>ZBDBA@orcl11g>ZBDBA@orcl11g>select rowid,dbms_rowid.rowid_object(rowid) robject, 2 dbms_rowid.rowid_relative_fno(rowid) fno, 3 dbms_rowid.rowid_block_number(rowid) bno, 4 dbms_rowid.rowid

First, describeStatic code blocks for classes in Java, Construction code blocks, constructor methods, initialization order of static members: First , when the class is loaded, allocate the memory space for the static member variable in the class and give it a default value (the integer type is 0, the float type is 0.0, the Boolean is false, the character type is ' \u0000 ', the reference type is null); Seco

) {NewHelloa (); }}classHellob { PublicHellob () {System. out. println ("I ' M B class"); } Static{System. out. println ("Static B"); } {System. out. println ("B"); }}Operation Result:Static BStatic ABI ' M B classAI ' M A classParsing: Output order: Parent class static code block > Subclass Static code block > parent non-static code block > Parent class constructor > subclass non-static code block > Subclass constructor;Difference:Static code blocks