Inheritance and copy constructor

[invisible.hippo]

Hi, i am confused between two different example of inheritance and copy constructor

In the first example

class Baz
{
        public:
                Baz( std::string foo ) : foo( foo ) { }
        private:
            std::string foo;
};
 is roughly equivalent to
class Baz
{
        public:
                Baz( std::string foo )[QUOTE][/QUOTE]
                {
                    this->foo = foo;
                }
        private:
            std::string foo;
};

Baz( std::string foo ) : foo( foo ) { }

If i am not wrong, the above means that an argument is passed into foo funcion. Then the foo function will store this value. Next the Baz function contain 1 private member call string foo. String foo will take in 1 argument. This argument is known as foo and the value of this foo is from the function know as foo.

Spoiler

http://www.cprogramming.com/tutorial/initialization-lists-c++.html

Why is the example shown below giving a different explanation

Foo::Foo( const Foo& f ) :  x( f.x ),  str( strdup( f.str ) ){}   

In this particular case, the above is equivalent to

Foo::Foo( const Foo& f )
{
    x = f.x;
    str = strdup( f.str );
}

Spoiler

http://www.cplusplus.com/forum/beginner/11349/

In the above example shouldnt it be like

Foo::Foo( const Foo& f )
{
    f = f.x;
}

Lastly am i correct for the concept of inheritence

class ten
{
protected:
int a,b,c
public:
void ten();
};


class one
{
private:
int a,b,c
public:
void one();
};


void one:ne(int 1,int 2,int 3) : ten(int 10,int20,int30)
{
1 = 30;
2 = 20;
3 = 30;
a=1;
b=2;
c=3;
}

 

[davidktw]

http://www.cplusplus.com/articles/y8hv0pDG/

http://www.cplusplus.com/doc/tutorial/inheritance/

 

[invisible.hippo]

http://www.cplusplus.com/articles/y8hv0pDG/

http://www.cplusplus.com/doc/tutorial/inheritance/

thank you