How to use namespaces in C++?

In C++, namespaces are used to prevent naming conflicts by dividing the global scope into different areas, allowing different code blocks to use the same names without conflicts.

The usage method of namespaces is as follows:

1. domain

   or

   a category or group of related items, ideas, or activities.

namespace myNamespace {
    // 命名空间中的代码
}

1. scope or domain

myNamespace::myFunction(); // 调用命名空间中的函数
int x = myNamespace::myVariable; // 访问命名空间中的变量

1. To simplify the use of namespaces, aliases can be assigned to them. For example:

namespace ns = myNamespace;
ns::myFunction(); // 使用别名访问命名空间中的函数

1. Nesting of namespaces: It is possible to nest one namespace within another, for example:

namespace outerNamespace {
    namespace innerNamespace {
        // 内部命名空间中的代码
    }
}
outerNamespace::innerNamespace::myFunction(); // 访问嵌套的命名空间中的函数

Using namespaces effectively manages the namespaces in the code, avoiding naming conflicts and enhancing the code’s maintainability and readability.