How to inherit c++ header file?

Question

In java there is no header file. We import Class and use function. We can also extend them. In C++ there is header file. We include them and use function. Now my question, how to inherit them like java extends and is it possible?

Answer 1

Every program has its own way of doing something. In c++ you can do like:

//filename foo1.h
class foo1{
}

Now inn another file say foo2.h

//filename foo2.h

    #include "foo1.h"
    class foo2 : public foo1
    {
    }

Answer 2

Java combines two things which C++ separates: the class definition and the definition of its members.

Java:

class Example {

    private String s;

    protected static int i = 1;

    public void f() {
        System.out.println("...");
    }

    public Example() {
        s = "test";
    }
}

C++ class definition:

class Example
{
private:
    std::string s;

protected:
    static int i;

public:
    void f();
    Example();
};

C++ definition of members:

int Example::i = 1;

void Example::f()
{
    std::cout << "...\n";
}

Example::Example() :
    s("test")
{
}

The separation into *.h and *.cpp files is purely conventional . It typically makes sense to put the class definition into the *.h file and the definition of the members into the *.cpp file. The reason why it makes sense is that some other code using the class only needs the class definition , not the definition of its members. That "other code" includes subclasses. By providing the class definition in a separate file, a user of the class can just #include the header and doesn't need to bother with the *.cpp file.

(Note that the *.cpp file, too, needs to #include its corresponding header file.)

If that looks complicated to you, view it from a different perspective. It allows you to modify the definition of the members without users of your class having to recompile their code. This is a big advantage of C++ compared to Java! The larger your project, the more important an advantage it becomes.

Answer 3

在具有继承/多态性的 c++ 中执行此操作的一般方法是声明以下内容：

#include "myheaderfile.h"