Getting wrong output. Garbage value - c++

Question

Problem is, on execution, the value of roundCost I'm getting is
something like -1220673834. I post the entire program because I'm not
sure where I'm going wrong.
Note: I was asked to take all variables as double type and later,
roundCost should be of type int. So I used type conversion there.
#include<iostream>
using namespace std;
class Restaurant{
private:
double tip, tax,totalCost,mealCost, tipPercent, taxPercent;
int roundCost;
public:
int tipCalc(double)
{
tip=mealCost*(tipPercent/100);
return tip;
}
int taxCalc(double)
{
tax=mealCost*(taxPercent/100);
return tax;
}
int totalCost1()
{
totalCost=mealCost+tip+tax;
return totalCost;
}
int roundCost1(double)
{
roundCost=(int)totalCost;
return roundCost;
}
}; // class ends
int main()
{
double mealCost, tipPercent, taxPercent, totalCost;
int roundCost;
Restaurant ob1;
cout<<"\n Enter mealCost \n";
cin>>mealCost;
cout<<"\n Enter mealtipPercent \n";
cin>>tipPercent;
cout<<"\n Enter mealtaxPercent \n";
cin>>taxPercent;
ob1.tipCalc(tipPercent);
ob1.taxCalc(taxPercent);
ob1.totalCost1();
ob1.roundCost1(totalCost);
cout<<"\n Round of cost is "<<roundCost<<endl;
return 0;
}

Answer 1

One thing you seem to be missing is that variables in your class have a different scope then variables in your main. You set the mealcost in your main from cin but you never passed this variable to the class. I changed this to be done using a constructor that sets the meal cost on creation. In every class you make you should always add a constructor. Also, you should be naming the variables your passing to functions and then using the same name in the function. For example in the tax percent function i pass double t, t is the percent, we then use t in the calculation. Your round cost variable was also private so you needed to output it via a function.
Also int functions will return a value, if you are using this type of function you should be assigning the return variable to something, but since you are just setting things in your class you can use void functions for most. The only time you use a value in the main is in the roundcost so this one is good to have it return a value. As it is int (which i assumed you wanted) it will get no decimal points and it will simply cut off any decimals in the total cost (ie 75.75 would become 75).
#include<iostream>
using namespace std;
class Restaurant{
private:
double tip, tax,totalCost,mealCost;
int roundCost;
public:
Restaurant (double m)
{
mealCost = m;
}
void tipCalc(double t)
{
tip=mealCost*(t/100.0);
}
void taxCalc(double t)
{
tax=mealCost*(t/100.0);
}
void totalCost1()
{
totalCost=mealCost+tip+tax;
}
int roundCost1()
{
roundCost=(int)totalCost;
return roundCost;
}
}; // class ends
int main()
{
double mealCost, tipPercent, taxPercent, totalCost;
int roundCost;
cout<<"\n Enter mealCost \n";
cin>>mealCost;
Restaurant ob1(mealCost);
cout<<"\n Enter mealtipPercent \n";
cin>>tipPercent;
cout<<"\n Enter mealtaxPercent \n";
cin>>taxPercent;
ob1.tipCalc(tipPercent);
ob1.taxCalc(taxPercent);
ob1.totalCost1();
cout<<"\n Round of cost is "<<ob1.roundCost1()<<endl;
return 0;
}
Try to do a bit more research next time by using a debugger, outputting cout statements regularly and searching for the errors you find but this will give you a working code this time.