Jency LeeLinks: http://www.cnblogs.com/Jency/articles/C_Cplusplus_define.html1. Simple define Definition #define MaxTime + A simple maxtime is defined, which represents 1000 if you write in the program if (i Compiler replaces maxtime with 1000 before processing the code. The definition of looks similar to a normal const definition, but it is also different because the definition of
The Define () function defines a constant.define () functions: Defines a constant. Constants is much like variables, except for the following differences: constants [constant] and variables [variable] There are many similarities, so it is easy to confuse; Let's enumerate the differences between constants [constant] and variables [variable]: A constant's value cannot be changed after it is set a constant value cannot be changed after it has been specif
Http://blog.sina.com.cn/s/blog_686188ef0100klku.html#define是C语言中提供的宏定义命令, the main purpose is to provide programmers with certain convenience in programming, and to a certain extent, improve the efficiency of the program, but students often do not understand the nature of the command in learning, always create some confusion here, in the programming of the misuse of the command, To make the program run inconsistent with the intended purpose, or to rea
#define是C语言中提供的宏定义命令, the main purpose is to provide programmers with certain convenience in programming, and to a certain extent, improve the efficiency of the program, but students often do not understand the nature of the command in learning, always create some confusion here, in the programming of the misuse of the command, To make the program run inconsistent with the intended purpose, or to read the program written by others, the results of the
Let's look at a few examples
(1) struct{int x; int y;} Test1;
Well, define the structure test1,
test1.x and test1.y can be used in the statement.
(2) struct test {int x; int y;} Test1;
Well, define the structure test1,
test1.x and test1.y can be used in the statement. Compared
with 1, the province wrote Test
(3)
typedef struct TEST
{int x; int y;
} TEXT1,TEXT2;
Only said that the structure of the (
: This article mainly introduces the difference between const and define in php (supplement). If you are interested in PHP tutorials, refer to it. A constant is the identifier (name) of a simple value ). As its name implies, this value cannot be changed during script execution (except for so-called magic constants, they are actually not constants ). Constants are case sensitive by default. Constant identifiers are always capitalized.
You can use the
In # define, the standard defines only # and # #两种操作. #用来把参数转换成字符串, # #则用来连接两个前后两个参数, turn them into a string.#define CONN (x, y) x# #y//connection X, Y#define TOCHAR (x) #@x//Plus Single quote#define TOSTRING (x) #x//plus double quotation marksRecently read the COM related information, see CCmdTarget Implement COM int
#define是C语言中提供的宏定义命令, the main purpose is to provide programmers with a certain degree of convenience in programming, and to a certain extent to improve the efficiency of the program, but students often do not understand the nature of the command, always here to create some confusion, the programming misuse of the command, So that the operation of the program is inconsistent with the intended purpose, or read the program written by others, the results
Macro definition in C # define usage,
# Define is a macro definition Command provided in C language. Its main purpose is to provide programmers with some convenience in programming and improve the program running efficiency to a certain extent, however, when learning this command, students often cannot understand the essence of the command, and there is always some confusion here. The command is misused dur
# Define is a macro definition Command provided in C language. Its main purpose is to provide programmers with some convenience in programming and improve the program running efficiency to a certain extent, however, when learning this command, students often cannot understand the essence of the command, and there is always some confusion here. The command is misused during programming, so that the program runs differently from the expected purpose, or
1. Define a simple constant: Define a constant to facilitate modification. (do not add a semicolon to the end !) # Define n 1000 is equivalent to const int n = 1000, but slightly different, define is just a simple replacement, rather than using it as a quantity. 2. defining simple functions: note that brackets are ofte
# Define is a macro definition Command provided in C language. Its main purpose is to provide programmers with some convenience in programming and improve the program running efficiency to a certain extent, however, students often cannotUnderstanding the essence of this command always creates some confusion here. This command is misused during programming to make the program run differently from the expected purpose, or when reading a program written
. Let's take a closer look at the msdn example and have a good understanding.
The following is an example of how to define a Unified Version macro.
Assume that the project contains the resource script file resource. RC, and the unique version number is stored in define. h. Other CPP files that require version numbers contain this file.
Let's take a look at define
For a long time, macro definition # define is used to define some simple constants. At most, it is used to define a function. It seldom pays attention to macro definition usage. Until the following code is displayed:
#define PLAYSOUNDEFFECT(...) \[[GameManager sharedGameManager] playSoundEffect:@#__VA_ARGS__]
I have
The difference between define () and const in php is described in detail. In php, both define () and const () can define constants. So what is the difference between define () and const? many programmers do not understand this, next I will introduce some differences between define
Difference between typedef and # define
The benefits of renaming constants using macro definitions: The program is easy to implement and easy to maintain and modify; 1) # define is a pre-processing command that performs simple replacement during compilation and preprocessing without checking the correctness, if the meaning is correct or not, possible errors are discovered and an error is reported only when
1, define--(no parameter macro definition)Usage: The general form is: #define Identifier string(1) "#" means that it is a pre-processing command, usually "#" is the pre-processing command;"Define" defines the command for the macro; "identifier" is the defined macro name; "string" can be a constant, an expression, a string, and so on.(2) In addition to the frequen
In php, both define () and const () can define constants. So what is the difference between define () and const? many programmers do not understand this, I will introduce you
In php, both define () and const () can define constants. So what is the difference between
The string in C is really too many places to pay attention to, yesterday in the knowledge to see some of the problems to think carefully, I still do not understand ...These days began to listen to the University of Zhejiang University Onge teacher
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