Class object will not push_back onto vector - c++

Question

Compiles and everything except adding in a 'ship'
Constructor for ship
Ship::Ship(std::string name, int length, std::string show) {
std::string _name = name;
int _length = length;
std::string _show = show;
}
void Ships::buildShip() {
std::string name, show;
int length = 0;
std::cout << "What is the name of the ship? ";
std::cin >> name;
std::cout << "How long is the ship in feet? ";
std::cin >> length;
std::cout << "What show/movie is the ship from? ";
std::cin >> show;
std::cout << std::endl;
Ship ship(name, length, show);
addShip(ship);
}
void Ships::addShip(Ship &ship) {
ships.push_back(ship);
}
I'm sure it's something very obvious, I've searched the web and found nothing helpful. I only took snippets from my code if anything else is needed let me know. Thanks in advance!
/Ship.h
#pragma once
#include <string>
class Ship {
std::string _name;
int _length;
std::string _show;
public:
Ship(){
std::string name = _name;
int length = _length;
std::string show = _show;
};
Ship(std::string _name, int _length, std::string _show);
std::string getName();
int getLength();
std::string getShow();
};
/Ship.cpp
#include <string>
#include "Ship.h"
Ship::Ship(std::string name, int length, std::string show) {
std::string _name = name;
int _length = length;
std::string _show = show;
}
std::string Ship::getName() {
return _name;
}
int Ship::getLength() {
return _length;
}
std::string Ship::getShow() {
return _show;
}
/Ships.h
#pragma once
#include <vector>
#include "Ship.h"
class Ships {
std::vector<Ship> ships;
public:
void addShip(Ship &ship);
int getCount();
Ship getLongestShip();
void buildShip();
int getNumberOfShipsLongerThan(int input);
void displayShips();
};
/Ships.cpp
#include "Ships.h"
#include <iostream>
void Ships::addShip(Ship &ship) {
ships.push_back(ship);
}
int Ships::getCount() {
return ships.size();
}
Ship Ships::getLongestShip() {
Ship longestShip = ships[0];
for (Ship aShip : ships) {
if (longestShip.getLength() < aShip.getLength())
longestShip = aShip;
}
std::cout << "The longest ship is the " << longestShip.getName() << std::endl;
std::cout << "From end to end the length is " << longestShip.getLength() << std::endl;
std::cout << "The show/movie it is from is " << longestShip.getShow() << std::endl;
return longestShip;
}
int Ships::getNumberOfShipsLongerThan(int input) {
int longerThan = 0;
int size = ships.size();
for (int i = 0; i < size; i++) {
if (input < ships[i].getLength())
longerThan++;
}
return longerThan;
}
void Ships::displayShips() {
std::cout << " Complete Bay Manifest " << std::endl;
std::cout << "***********************" << std::endl;
for (int i = 0; i < ships.size(); i++) {
int a = i + 1;
std::cout << "Ship (" << a << ")" << std::endl;
std::cout << "Name: " << ships[i].getName() << std::endl;
std::cout << "Length: " << ships[i].getLength() << std::endl;
std::cout << "Show: " << ships[i].getShow() << std::endl<<std::endl;
}
}
void Ships::buildShip() {
std::string name, show;
int length = 0;
std::cout << "What is the name of the ship? ";
std::cin >> name;
std::cout << "How long is the ship in feet? ";
std::cin >> length;
std::cout << "What show/movie is the ship from? ";
std::cin >> show;
std::cout << std::endl;
Ship ship(name, length, show);
addShip(ship);
}
/driver.cpp
#include <iostream>
#include "Ship.h"
#include "Ships.h"
void menu();
Ship buildShip();
void shipsInBay(Ships &ships);
void processDirective(int choice, Ships &ships);
void longerThan(Ships &ships);
int main() {
std::cout << "Welcome to Daniel Mikos' Ship Bay!" << std::endl << std::endl;
menu();
system("PAUSE");
return 0;
}
void menu() {
Ships ships;
int choice = 0;
std::cout << "Please make a selection" << std::endl;
std::cout << " (1) Add a ship to the bay" << std::endl;
std::cout << " (2) How many ships are already in the bay?" << std::endl;
std::cout << " (3) Which ship is the longest? " << std::endl;
std::cout << " (4) Ships longer than ___? " << std::endl;
std::cout << " (5) Manifest of all ships currently logged" << std::endl;
std::cout << " (6) Exit" << std::endl;
std::cout << " Choice: ";
std::cin >> choice;
processDirective(choice, ships);
}
Ship buildShip() {
std::string name, show;
int length = 0;
std::cout << "What is the name of the ship? ";
std::cin >> name;
std::cout << "How long is the ship in feet? ";
std::cin >> length;
std::cout << "What show/movie is the ship from? ";
std::cin >> show;
std::cout << std::endl;
Ship ship(name, length, show);
return ship;
}
void shipsInBay(Ships &ships) {
int count = ships.getCount();
std::cout << std::endl;
std::cout << "There is currently " << count;
std::cout << " ship(s) in bay" << std::endl << std::endl;
}
void longerThan(Ships &ships) {
int input = 0;
std::cout << "Find ships longer than? ";
std::cin >> input;
std::cout << "There are " << ships.getNumberOfShipsLongerThan(input) << "longer than " << input << "feet";
}
void processDirective(int choice, Ships &ships) {
if (choice == 1)
buildShip();
if (choice == 2)
shipsInBay(ships);
if (choice == 3)
ships.getLongestShip();
if (choice == 4)
longerThan(ships);
if (choice == 5)
ships.displayShips();
menu();
}
There is all of my code

Answer 1

To add an object to a vector of objects use emplace_back() and pass the constructor arguments as arguments to emplace back. It will then build the object in place so call:
ships.emplace_back(name, length, show);
to construct your ship object in place. Your constructor also is incorrect as pointed out by #Kevin. You need to change it to:
this->_name = name;
this->_length = length;
this->_show = show;
assuming I've guessed your class design correctly.
EDIT
Tried to build a minimum example from this and this works fine for me:
Header.h
class Ship {
std::string _name;
int _length;
std::string _show;
public:
Ship();
Ship(std::string _name, int _length, std::string _show);
std::string getName();
int getLength();
std::string getShow();
};
class Ships {
public:
void addShip(Ship &ship);
void buildShip();
std::vector<Ship> ships;
};
and Source.cpp
#include "Header.h"
Ship::Ship(std::string name, int length, std::string show) {
this->_name = name;
this->_length = length;
this->_show = show;
}
void Ships::buildShip() {
std::string name = "Name";
std::string show = "Show";
int length = 0;
ships.emplace_back(name, length, show);
}
int main(int argc, char argv[])
{
Ships ships;
ships.buildShip();
std::cout << "Number of ships = " << ships.ships.size() << std::endl;
return 0;
}
Prints Number of ships = 1. Can you slim it down to something like this?