define use

1. Define (that is, host variable)The main role of the host variable is to act as an alternative variable, a medium in which the host environment can interact with Oracle . When you define a host variable by define, you must specify the variable

The difference between #define, const, typedef#define is not defining variables, it's just for text substitution.For example:#define PI 3.1415926float Angel;angel=30*pi/180;Then, when the program is compiled, the compiler will first "#define PI 3.141

#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,

Macro definition in many languages can see its shadow, C #, C++,c, and so on, especially the system API inside a lot of macro definition, looking very bluffing people. Reasonable use of macro definition, you can make your code look more standardized,

Definition: The # define Directive You can use the # define directive to give a meaningful name to a constant in your program. The two forms of the syntax are: Syntax # Define identifier token-stringopt # Define identifier [(identifieropt,...,

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(...) \[[

Reprinted from: Http://www.yonsm.net/read.php? 141 The version number may be used in many places in a VC project, such as the about dialog box and version resource. Changing these values one by one for each version is not only troublesome, but

Introduction To define a variable in the source file that is related to the line number, it is too slow to manually enter each time. This article describes how to use macro definitions to define variables related to line numbers. For example, we

Today, we have compiled some # define usage to share with you!1. Simple define Definition#define MAXTIME 1000A simple maxtime is defined, it represents 1000, if it is written inside the programif (IThe compiler replaces the maxtime with 1000 before

A constant is an identifier (first name) of a simple value. As the name implies, the value cannot be changed during script execution (except for the so-called magic constants, they are not constants). Changshime is considered to be case sensitive.