c++ cdi+示例

C ++中的本地类 (Local Class in C++)

In C++, generally a class is declared outside of the main() function, which is global for the program and all functions can access that class i.e. the scope of such class is global.

在C ++中，通常在main()函数外部声明一个类，该类对于程序是全局的，并且所有函数都可以访问该类，即此类的范围是全局的。

A local class is declared inside any function (including main() i.e. we can also declare a class within the main() function) and the scope of local class is local to that function only i.e. a local class is accessible within the same function only in which class is declared.

本地类在任何函数内声明(包括main()，即我们也可以在main()函数内声明一个类)，并且本地类的范围仅对该函数本地，即本地类只能在同一函数内访问在哪个类中声明。

Example:

例：

Here, we are declaring and defining two classes "Test1" and "Test2", "Test1" is declared inside a user-defined function named testFunction() and "Test2" is declares inside the main() function.

在这里，我们声明并定义了两个类“ Test1”和“ Test2” ，在一个名为testFunction()的用户定义函数中声明了“ Test1”，在main()函数中声明了“ Test2” 。

Since classes "Test1" and "Test2" are declared within the functions, thus, their scope will be local to those functions. Hence, "Test1" and "Test2" are local classes in C++.

由于在函数中声明了“ Test1”和“ Test2”类，因此它们的作用域对于这些函数而言是局部的。 因此， “ Test1”和“ Test2”是C ++中的本地类 。

Program:

程序：

#include 
    
     using namespace std;//A user defined functionvoid testFunction(void){
       //declaring a local class    //which is accessible within this function only    class Test1    {
           private:            int num;        public:            void setValue(int n)            {
                   num = n;            }            int getValue(void)            {
                   return num;            }    };        //any message of the function    cout<<"Inside testFunction..."<
    

Output

输出量

Calling testFunction...Inside testFunction...Value of Test1's num: 100Inside main()...Value of Test2's num: 200

翻译自:

c++ cdi+示例