post  [ASK] C++ about friend function

damzeta (1)   Link to this post
Hello senior2, I'm still dummy in C++. There are something that i want to ask.
There is a little program my lecturer gave.

#include <iostream.h>
#include <iomanip.h>
class PhoneNumber
{
friend ostream &operator<<( ostream&, const PhoneNumber & ); (***)
friend istream &operator>>( istream&, PhoneNumber & ); (***)
private:
char areaCode[ 4 ];
char exchange[ 4 ];
char line[ 5 ];
};


ostream &operator<<( ostream &output, const PhoneNumber &num ) (***)
{ output << "(" << num.areaCode << ") " (***)
<< num.exchange << "-" << num.line; (***)

return output;
}

istream &operator>>( istream &input, PhoneNumber &num ) (***)
{
input.ignore(); (***)
input >> setw( 4 ) >> num.areaCode; (***)
input.ignore( 2 ); (***)
input >> setw( 4 ) >> num.exchange; (***)
input.ignore(); (***)
input >> setw( 5 ) >> num.line; (***)
return input; (***)
}

void main()
{ PhoneNumber phone; // create object phone
cout << "Enter phone number in the form (123) 456-7890:\n";

cin >> phone;
(***)

cout << "The phone number entered was: ";

cout << phone << endl; (***)
}

Please give a comment or explanation in the line that i noted with (***), because i don't understand.
For line that un-noted, I already knew teh meaning of that line.
Thanks before for the answer Senior...
jsmith (3099)   Link to this post
In other words, you know nothing about the problem since you've marked virtually every line.

I would suggest starting by reading up on C++ syntax.

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