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Const is used for the definition of class member constants. it cannot be modified after definition, and define is used to define global constants, so that we can access but cannot change it elsewhere, we will list the details below. note: define cannot be defined in... const is used for the definition of class member constants. it cannot be modified after definit

There are two ways to define constants in C #, one called Static constants (Compile-time constant) and the other is called Dynamic constants (Runtime constant). The former is defined by "const", which is defined by "ReadOnly". For static constants (Compile-time constant), it is written in the following ways: public const int max_value = 10; Why do you call it a static constant because, as the above declaration can be interpreted as follows (note: T

is a shopping cart that stores the goods purchased from the store. Members of the club can enjoy a 10% discount, so the value can be saved as a constant: The code is as follows Copy Code Private Const Memberdiscountpercentage as single=0.1 After you have calculated the total price of an order, you can use the constant just as you would any other variable: The code is as follows Copy Code Memberdiscount=subtotal=memberdiscountpe

Usage and difference between typedef and # define 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 [10];Typedef (int *) pint; Typedef can be enhancedProgramBut it also has some disadvantages such as "non-intuitive.

In general, we define a constant using # define, #define的本质是文本替换, for example, # define INT_PTR int*, when we use a int_ptr,int_ptr a, B, which is equivalent to an INT * A, A, a, b; That is, define a pointer variable A and integer variable B, which is a common scenario for #

1 NO parameter macro definitionThe macro name of the parameterless macro is not followed by a parameter.The general form of its definition is:#define Identifier stringWhere the "#" indicates that this is a preprocessing command. All that begin with "#" are pre-processing commands. "Define" defines the command for the macro. "Identifier" is the name of the macro defined. A "string" can be a constant, an expr

Note: Define cannot be defined in a class, and the const must be defined in a class, and the const must be accessed by the class name:: Variable name 1. Const is used for class member variable definition once defined and cannot change its value. Define defines global constants that can be accessed anywhere.2, define can not be defined in the class and Const.3. C

Original article address: Http://blog.csdn.net/kindazrael/article/details/8108868 In C, Preprocessor is a powerful tool that makes your code easier to read and modify. With preprocessing code, you can redefine a part of the code to make your code more suitable for your style. Preprocessor is processed in advance before the code is compiled. The pre-processing code starts with a pound sign.1. About #define #defineDeclarations are mainly used to assign

#define宏定义在C系开发中可以说占有举足轻重的作用. The underlying framework does not have to say, in order to compile optimization and convenience, as well as cross-platform capabilities, macros are heavily used, it can be said that the bottom of development left define will be unable to move. When developing at a higher level, we put more emphasis on business logic and seem to have little use and reliance on macros.But the ben

(PHP 5 >= 5.3.0, PHP 7) You can also define multiple namespaces in the same file. There are two syntactic forms of defining multiple namespaces in the same file. Example #1 Define multiple namespaces, simple combination syntax It is not recommended to use this syntax to define multiple namespaces in a single file. It is recommended that you use the syntax in