CODEWITHSUNDEEP
c++visual-c++
Steve Proschenko
Steve Proschenko

Reputation: 37

C++ comparing input string with a string gives me a warning of conversion from double to int - possible data loss

i have to write a program that asks user for weight and a planet name. Program has to output how much user would weight on that planet. For some reason i get errors: " '=': conversion from 'double' to 'int', possible loss of data.

Before i was trying to use (planet == Mercury) but still no luck.

Here is my code:

    // ConsoleApplication5.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>
#include <string>
#include <sstream>
#include "ConsoleApplication5.h"

using namespace std;

int main()
{
    cout << "Assignment 05" << endl;


    int weight = 0;
    string planet = "";
    int weightOnplanet;
    string entry = "You entered a weight of ";

    string Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto;

    cout << "Please Enter Weight <as an integer of pounds>: " << endl;
    cin >> weight;
    cout << "Please Enter Planet name <ie: Earth>: " << endl;
    cin >> planet;
    cout << entry << weight << " and a planet name of " + planet << endl;



    if (planet == Mercury)
    {
        weightOnplanet = weight * 0.4155;
        cout << "On a " + planet + " your weight in pounds would be " << weightOnplanet << endl;
    }
    else if (planet == Venus)
    {
        weightOnplanet = weight * 0.8975;
        cout << "On a " + planet + " your weight in pounds would be " << weightOnplanet << endl;
    }
    else if (planet == Earth)
    {
        weightOnplanet = weight * 1.0;
        cout << "On a " + planet + " your weight in pounds would be " << weightOnplanet << endl;
    }
    else if (planet == Mars)
    {
        weightOnplanet = weight * 0.3507;
        cout << "On a " + planet + " your weight in pounds would be " << weightOnplanet << endl;
    }
    else if (planet == Jupiter)
    {
        weightOnplanet = weight * 2.5374;
        cout << "On a " + planet + " your weight in pounds would be " << weightOnplanet << endl;
    }
    else if (planet == Saturn)
    {
        weightOnplanet = weight * 1.0677;
        cout << "On a " + planet + " your weight in pounds would be " << weightOnplanet << endl;
    }
    else if (planet == Uranus)
    {
        weightOnplanet = weight * 0.8947;
        cout << "On a " + planet + " your weight in pounds would be " << weightOnplanet << endl;
    }
    else if (planet == Neptune)
    {
        weightOnplanet = weight * 1.1794;
        cout << "On a " + planet + " your weight in pounds would be " << weightOnplanet << endl;
    }
    else if (planet == Pluto)
    {
        weightOnplanet = weight * 0.0899;
        cout << "On a " + planet + " your weight in pounds would be " << weightOnplanet << endl;
    }
    else
        cout << "Unknown Planet" << endl;

    system("pause");
    return 0;
}

Upvotes: 0

Views: 62

Answers (2)

Gaurav Sehgal
Gaurav Sehgal

Reputation: 7542

The warning you get is for 

weightOnplanet = weight * 0.4155;

Since weightOnPlanet is int and weight * 0.4155 is double you will be loosing precision.You probably want weightOnplanet to be double and not int.

Just to mention if (planet == Mercury) would be comparing planet to an empty string which is why you would get undesired result, until you do what @ErrorAtLine0 mentioned.

Upvotes: 2

ErrorAtLine0
ErrorAtLine0

Reputation: 189

Each planet variable (Mercury, Venus, etc) should have an actual value such as:

Mercury = "Mercury";

A string doesnt initialize with the name of the variable, you have to actually give it a value.

You don't even have to have a variable for every planet. You could just do this:

if(planet == "Mercury")

Upvotes: 3

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