在默认构造函数中插入数据后，我没有任何输出，但是我不确定为什么不这样做

Question

So I am using default constructor to insert individual entries into memory and then read them by calling getBookInfo() method. When I try just to do a test run with only one variable I am not getting anything there even if I am calling getBookInfo() after I inserted the data.

Why is that?

Main.cpp

#include <iostream>
using namespace std;

#include "Book.h"

void main()
{
    Book book;

    book.setTitle("Advanced C++ Programming");
    book.setAuthorName("Linda", "Smith");
    book.setPublisher("Microsoft Press", "One Microsoft Way", "Redmond");
    book.setPrice(49.99);
    book.getBookInfo(); // <-= this should be output

    int i;
    cin >> i;
};

Book.cpp

#include <iostream>
#include <sstream>
using namespace std;

#include "Book.h"

Book::Book()
{
}

void Book::setTitle(string  title)
{
    title = title;
}


void Book::setPrice(double price)
{
    price = price;
}

string Book::convertDoubleToString(double number)
{
    return static_cast<ostringstream*>( &(ostringstream() << number) ) -> str();
}

// this should be output
string Book::getBookInfo()
{
    stringstream ss;
    ss << title << endl << convertDoubleToString(price) << endl;

    return ss.str();
}

Answer 1

Change

void Book::setTitle(string  title)
{
    title = title;
}

to

void Book::setTitle(string  title)
{
    this->title = title;
}

and the same change wherever this kind of code occurs. As written, the code assigns the value of the argument title to the argument title , ie it does nothing. The compiler probably warned you about this.

Or, as @hmjd said, change the names of the arguments.

Answer 2

You need to capture the data returned from getBootInfo(), for example

string result = book.GetBookInfo();
cout << result;