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Only for the speed problem, as for the usage for the time being, see online Some people say that const belongs to the structure of grammar, the speed will be higher than define function several times, I need a professional argument, is it true? Now that const can be used outside of the class, is it a priority when you define constants? Reply content: Only for the speed problem, as for the usage for the

anonymous function is defined, where jquery represents the argument for this anonymous function. Often used in jquery plug-in development, the role of defining the plug-in's private domain.Third, the development of jquery plug-in standard structure1, define the scope: Define a jquery plug-in, the first to put the plug-in code in a place that is not disturbed by the outside world. If you are professional, y

First on the source code:The file is portmacro.h, derived from the underlying code in the dynasty project (Nvic Interrupt control section)1 #definePortnvic_int_ctrl_reg (* (volatile uint32_t *) 0xe000ed04ul)2 #definePortnvic_pendsvset_bit (1UL 3 4 5 voidVportyield (void )6 {7 /*Set a PENDSV to request a context switch.*/8Portnvic_int_ctrl_reg =Portnvic_pendsvset_bit;9 Ten /*barriers is normally not required but does ensure the code is completely One within the specified behaviour for the

typedef: Create aliases for data types;such as: typedef char int8;#define: A string is represented by a macro name;Example: #define INT8 CharThe difference between the two:1. You can extend the name of the macro type with other type specifiers, but not for the type defined by the typedef;such as: typedef char int8;#define INT8 Charunsigned INT8 i; No problemunsig

The geometry artboard is a kind of common mathematics software, its function is very many. Today we are going to show you how to define a coordinate system in a geometry artboard? Defining the coordinate system is the first command in the drawing menu of the geometry artboard, which users can use to create or define a coordinate system: Including coordinates origin, unit length, axis, and so on. once the g

typedef: Used in computer programming languages to define simple aliases for complex declarations (aliases to types, overall type substitution), and some differences from macro definitions. It is a kind of storage class keyword, and auto, extern, mutable, static, register and other keywords can not appear in the same expression, the definition of variable syntax, there is a typedef that defines the name of the type, No typedef indicates that a variabl

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. By convention constant identifiers are always capitalized. The constant name and any other PHP tags follow the same naming conventions. A valid constant name begins with a letter or underscore followed by any letter, number, or underscore. This is ex

Typedef Usage Purpose 1: Define a type of Alias, not just a simple macro replacement. It can be used as multiple objects that declare the pointer type at the same time. For example: Char * pA, PB; // most of them do not conform to our intention. It only declares a pointer to a character variable, // And a character variable; The following are feasible: Typedef char * pchar; Pchar Pa, PB; Purpose 2: Used in the ol

As soon as you define a custom constructor, the default constructor is silently removed from the class and is no longer available! Therefore, if you wish to allow the object user to create an instance of your type with the default constructor, as well as your custom constructor, you must explicitly redefine the default. Once a custom constructor is defined, the default constructor is automatically removed from the class and no longer valid! Ther

1. Const In programming, we generally use constants to define the constant values that cannot be changed during runtime. Let's take a look at the const in PHP. There is nothing to say about this, let's just talk about it for the sake of Knowledge perfection. When defining a constant, we can use const to modify this constant,The constant modified with const is a little different from other constants, that is, do not use "$" before the constant name. Re

I think the materials I have prepared are quite important. 1) # define is a pre-processing command. It is a simple replacement during compilation and pre-processing, and does not check the correctness. It does not mean that it is correct or not, possible errors are detected and reported only when the expanded source program is compiled. For example: # Define PI 3.1415926 In the program: Area = pI * r will

For example: to write a header file test.h #ifndef _test_h #define _TEST_H//is typically an uppercase file name ············ #endif 1. For example, you have two C files, and all two C files include the same head file. At compile time, the two C files will be compiled together into a running file, so the problem is, a lot of declaration conflicts. Suppose you have 4 files in your project, respectively, A.cpp,b.h,c.h,d.h. NBSP A.cpp Head is: #incl

Read the manual. Define defined constants Allow only: Only scalar and null are allowed. The type of the scalar is integer, Float,string, or Boolean. It is also possible to define the type of a constant value as resource, but this is not recommended, which may cause an unknown condition to occur. Read the PHP source today, found that the second parameter of define

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 amount of code is not suitable for encapsulation, then we will think of C + + keyword define. In fact, it is wise of you to meet the above situation and think of something else----template, and we'll talk about

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 bricks to the prawns ~~~ Embedded system programming requires programmers to use C language to access a fixed memory address. Since it is an address, according to

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 dataset based on the data source, or you can define a multi-dimensional da

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 together to see it. The definition of 1.PHP constants and the use of examples to explain constants we can understand as the amount of constant value. Constants ar

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 process, but it does not actually allocate memory space, such as:typedef int INT;typedef int ARRAY[10];typedef (INT*) PINT;typedef can enhance the readability of the program, as well as the flexibility of ident

First, preprocessing commands he is not a constant!!!! Let's look at a piece of code #define @ "Avatar" if (false) { #define AVATAR @ " NSLog"} (Avatar); How much does this code output, we define "avatar" for 60, and then redefine "Avatar" in a code that never executes, the code in theif statement never executes, but at compile time , the compi

[Android-tips] Unable to execute dex: Multiple dex files define solution, android-tipsdex Well, I already thought about not moving android in the future. I didn't expect it to be a heavy job because of the competition. Android has many problems due to incomplete eclipse. For example, the problem encountered today is Unable to execute dex: Multiple dex files define. [2011-10-23 16:23:29 - Dex Loader] Unable