uplink definition

Array: is a set of related variables An array is a set of related data, an array is actually a series of variables, the array can be divided into one-dimensional array, two-dimensional array, multidimensional array The data is a bit Do not use an array to define 100 integer variables: int i1;int i2;int i3 Use array definition int i[100]; Array definition: int i[100]; it's just a pseudo code, just an ex

Macro Definition #define APLLCON0 * (volatile unsigned int *) 0xff500100), value is virtual address question : GDB tracing Debug When you want to view the value of this macro, you are prompted as follows: No symbol "APLLCON0" in the current context. Analysis : Reference http://blog.csdn.net/jibing57/article/details/7439631 The compiler does not compile the macro definition extension information into

Macro definition that contains if When the macro definition contains an IF 1) define the following macros#define DC (P) if (foo (p)) fun (p) Used in the following environment if (k>n) DC (k); Else DC (n); After the macro is replaced, the following if (k>n) if (foo (k)) Fun (k); Else if (foo (n)) Fun (n); Visible, the original if and else are no longer paired. 2 To avoid such problems, we can define a ma

We usually need to according to customer demand for the results of the query to provide customers with their own definition of the sort, then we usually need to implement the SQL is what, many other information summarized such as the following (not good and wrong to point out):first, let's say that we just need to sort the application in a particular program in the following way, we just have to set the sort at the SQL statement level: 1, in accordanc

We use Activiti (5.14 version) as the process engine, and today we find a problem in the product, the approval record of a process,The activity name recorded in the Activity instance table (Act_name of the Act_hi_actinst table) is the name of the activity that does not exist in the process.Confirmed that the process has not been modified.Later discovered is the problem of Activiti cache, our products are supported by multi-company use, each company uses a different database,Therefore, the proces

This article mainly describes the HTML5 menu label definition and usage examples, there are instances and examples of results in, which makes us more simple to learn, so please read this article about HTML5 menu tags HTML5 the definition and usage of the menu tag: HTML5 A toolbar with two menu buttons ("File" and "Edit"), each containing a drop-down list with a series of options: Two ways to use the m

node nodes are considered to be ordered from left to right, it is called ordered tree; otherwise, it is called an unordered tree. The fraternal nodes of the ordered tree cannot be exchanged.(9) Forest: A collection of trees is called a forest. There is a close relationship between trees and forests. Deletes the root node of a tree, and all its original subtrees are trees, constituting the forest. The root node of all the trees connected to the forest with one node is the tree. This node is call

Tags: mysql DDL creationFirst, the specific installation of MySQL here is not much to say, there are many online. You can find it on the Internet, there are installed version and compressed version.Second, verify that the database is installed successfully:Under DOS command line enter: Mysql-u root-p (the default is the direct return on it, if you do not set the password)If you set a password, you have to enter the password.Will log on to MySQL, there is a message for MySQL. Third,DDL: Data

the relationship between objects, can be recognized from the following file. 1 item.h: The Total object definition class, which defines the ' item ' class as the Total object class, since then, many subclasses are defined in this file to enrich and develop the objects that MySQL can handle. However, this class inherits from the ' Parse_tree_node ' class, which makes the object and lexical parsing associated, which is not a detailed explanation. 2 ite

Definition, deletion and modification of basic tables for data definitionDefinedFormat: CREATE table Example 1:CREATE TABLE Student (ID INT (one) PRIMARY KEY,NAME VARCHAR (one) UNIQUE);Example 2:CREATE TABLE Student (ID INT (11),NAME VARCHAR (11),PRIMARY KEY (ID),Poreign KEY (name) REFERENCES NAMES (name));ModifyFormat: ALTER TABLE[Add [Column] [Add [table-level integrity constraint]][Drop[column] [Drop constraint [Alter COLUMN Example 1 adding a colu

What is a class constant? What we can understand in PHP is that the value is constant, so what is a class constant? In fact, the class constants are also easy to understand, we can always keep the constant value of the class is called constants, and this constant can be called the class constant. Be sure to remember that you do not need to use the "$" symbol when defining and using constants. A class constant belongs to the class itself, not to an object instance, and cannot be accessed through

file of the class Person.h (which is usually done in this file), There is also a person.m file, which is generally implemented as defined in the header file. This is also a continuation of the C language of the project structure it. General header files are only responsible for defining functions, and. c files are responsible for implementing specific functions. It's similar here.Here's a look at the definition format for the class in the Person.h he

"0" written in front0.1) The purpose of this code:The purpose of this text is to explain the function of the local descriptor, its definition, initialization and jump, etc.0.2)The personal summary at the end of the article is dry, the preceding code is for reference only, and source code from Orange's implemention of a OS.0.3)Since the code in this article and the "Steps of the real mode and protected mode switching" source code has a similarity of 90

Always thought that my C language can still, although not superb, but at least more familiar with it. But a while ago read a tweet, and then Baidu a bit of C language is not the exact type. Found me. C language is not completely type and the use of a very wide range of delay definitions have no concept. These two days looked closely at the relevant concepts and experimented with the code.This article is structured as follows: Introduction to the concept of non-complete type of C languag

' Editconf.h:40:8: Error: ' std::string waitdurationg ' Previously declared Hereeditconf.cpp:56:8: error:redefinition of ' std::string timeoutpageg ' editConf.h:41:8: Error: ' std:: String Timeoutpageg ' previously declared hereeditconf.cpp:57:8: Error:redefinition of ' std::string TIMEOUTINCRG ' Editconf.h:42:8: Error: ' std::string TIMEOUTINCRG ' previously declared heremake: * * * [EDITCONF.O] Error 1Very confused, clearly defined only once!In factIn EditConf.h, there is the following code s

obtained through the system variable, directly through =, get is a null value. In fact, we follow the above understanding that the function is a command, in the shell to obtain the command return value, all need to get through the $? function scope, variable action rangeExample (test_fun2.sh): #!/bin/shecho $(uname);declare num=1000;uname(){ echo "test!"; ((num++)); return 100;}testvar(){ local num=10; ((num++)); echo $num;}uname;echo $?echo $num;testvar;echo $num; Let'

KDEV_T.H macro Definition ParsingThis header file is not much anyway, the direct reason is--met, just fix it!A variable of type dev_t is defined in Linux/types.h to hold the device number-including the main device number and the secondary device number. Dev_t is a 32-bit number, where 12 bits are used to represent the device number, and the remaining 20 bits are used to represent the secondary device number.Always do not make assumptions about whether

Macro definition Simple macroFormat: #define Identifier substitution list#define N 100int a[N];//N就是100Macros with parametersFormat: #define identifier (x1, x2, x3,...... xn) Replace list#define MAX(x, y) ((x) > (y) ? (x) : (y))Note: When the program compiles, it will replace the uppercase identifier with the original expression, so the program will increase at compile time.Advantages or DisadvantagesAdvantages① program may be a little faster② Macros

Java constant definition/** * Char type constant */private static final char char = ' A ';/** * byte type constant */private static final byte byte = 1;/** * Short Type Constant */private static final short short = 10;/** * int type constant */private static final int int = 100;/** * Long type constant */private s Tatic final Long long = 100;/** * Float type constant */private static final float float = 120f;/** * Double type constant */private static

1. class definition;2. Array of objects #includeusing namespacestd;class myfoo{private:intnum;string foostr;public:myfoo(inta,std::stringstr):num(a),foostr(str){cout} myfoo() //myfoo aSmple;如果自己写了构造函数，那么需要列出默认构造 // functions { } ~ Myfoo () { cout } }; Intmain (intargc,char*[]) { string strtmp ("I_love" ); myfoo G[3]={myfoo (1,strtmp), Myfoo (2,strtmp), Myfoo (3,strtmp)}; return 0; } 3.Foo.cpp:29:error:no m