what define

The difference between define () and const: Define () defines constants during the execution period, while Const defines constants at compile time. This will have a slight speed advantage (ie a slightly better performance), but it is not worth

Asynchronous modules define AMD and asynchronous modules amd It is called Asynchronous Module Definition, and is defined by Asynchronous components (or modules. AMD is a mechanism in which components and their dependencies can be asynchronously

I. Usage of typedef In C/C ++, typedef is often used to define an alias for an identifier and a keyword. It is part of the language compilation process, but it does not actually allocate memory space, such: Typedef int;Typedef int array

Difference between typedef and # define 1. typedef Typedef is the meaning of the type definition, but itInstead of defining a new type, you can create an alias for an existing type., Similar to the meaning of the reference,References are aliases of

The examples in this article describe how classes are defined in JavaScript. Share to everyone for your reference, specific as follows: JavaScript itself does not support object-oriented, it does not have an access control character, it does not

From: Http://stackoverflow.com/questions/2447791/define-vs-constSame point: Both can define constantsConst foo = ' Bar ';d efind (' foo ', ' Bar ');The disadvantage of const:1.const must be declared in Top-level-scope (top-level domain):For example:

Parse the differences between const and define in php. 1. const is used for defining class member variables. once defined, the value cannot be changed. Define defines global constants that can be accessed anywhere. 2. define cannot be defined in the

TypedefIt is a type-defined keyword that is used to declare Custom Data Types in computer programming languages and used with various original data types to simplify programming. #DefineIs a preprocessing command. Let's take a look. Typedef is a C

C #-# define condition compilation, Introduction: C # pre-processor commands will never be converted into executable code commands, but will affect all aspects of the compilation process. Commonly used pre-processor Commands include # define, #

1 similarities and differences as constants (0) SameBoth can be used to define constants;#define PI 3.14159//Macro ConstantsConst DOULBE pi=3.14159; Constant(1) different compiler processing methodsThe Define macro is expanded in the preprocessing

Let's say the following code is required to be compatible with three versionsThis will not complete the task.No mattertypedef enum{first,second,third,}; #define NUM third#if (num = = first) #define VAR 1#elif (num = = SECOND) # Define var

What do we often do with define? 1) define a constant 2) define a macro Why do not use define. The following two aspects are explained: 1) when we define a constant, we can use the following method: # Define aspect_patio 1.653 We know

Q: How do I define global variables in VC? A:Put in any fileUse extern declaration in other filesOr declare a Public Member in the App class.It can be used in other classes of the program.AfxGetApp () gets an App object pointer and converts it to

Try to use const and inline instead of # define This clause is best referred to as "try to use the compiler instead of preprocessing", because # define is often considered not part of the language itself. This is one of the problems. Let's look at

Http://blog.csdn.net/zhanglianpin Global variables should be variables that are allocated in memory and can be called by other modules using the extern keyword in C language. Therefore, it must be defined in the. C and. H files. This repetitive

When writing a program, we often encounter a problem where we need to write a lot of the same code, and the code structure is the same. Always want to encapsulate this code and then call directly, but if this code logic is not complex, and the

Understanding # define sreg (* (volatile unsigned char *) 0x5f)   Understanding # define sreg (* (volatile unsigned char *) 0x5f)This definition is always very strange. I don't know why. I have a little bit of experience today. Please submit more

using the multi-dimensional dataset wizard, you can easily define a simple multi-dimensional dataset in SQL Server 2005. This wizard helps you define measurement values and dimensions for cubes. In this wizard, you can define a multi-dimensional

PHP uses the Define () function to define a constant. The so-called constant refers to the value of the amount of constant, this article collects a few about the PHP constants of the article, I hope that you understand the PHP constants help, come

Transferred from: http://www.cnblogs.com/kerwinshaw/archive/2009/02/02/1382428.htmlI. Usage of typedefA typedef is commonly used to define an identifier and an alias for a keyword in the C + + language, which is part of the language compilation