Class Object, Display Speed of Vehicle

[CrazdKC]

Prompt written below. Current problem; all displayed current speeds are negative and incorrect.

Prompt: For this program I need to demonstrate class in a program that creates a Car object. I need the program to call an accelerate function 5 times, after each acceleration iteration of +5 mph I need it to display the current speed of the vehicle. I then need the program to call a brake function 5 times, after each deceleration iteration of -5 mph I need it to display the current speed of the vehicle. The speeds displayed should look something like this

The current speed of the vehicle is 5
... 10
... 15
... 20
... 25
... 20
... 15
... 10
... 5
... 0

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

class Car
{
private:
	double YearModel;
	string Make;
	double Speed;

public:
	Car(double, string, double);
	double getSpeed();
	double getModel();
	void accelerate();
	void brake();
};

double Car::getSpeed()
{
	return Speed;
}

Car::Car(double YearModel, string Make, double Speed = 0)
{

}

void Car::accelerate()
{
	Speed = Speed + 5;
}

void Car::brake()
{
	Speed = Speed - 5;
}

int main()
{
	double YearModel;
	string Make;
	cout << "Enter the vehicles year and make ";
	cin >> YearModel >> Make;

	Car myCar(YearModel, Make);
	for (int a = 0; a < 5; a++)
	{
		myCar.accelerate();
		cout << "The current speed of the vehicle is: " << myCar.getSpeed() << endl;
	}

	for (int b = 0; b < 5; b++)
	{
		myCar.brake();
		cout << "The current speed of the vehicle is: " << myCar.getSpeed() << endl;
	}
	system("Pause");
	return 0;
}

[TarikNeaj]

You never set Speed to a starting value, so Speed is currently equal to garbage.

Car::Car(double YearModel, string Make, double Speed = 0)
{

}

Car myCar(YearModel, Make);

You call the constructor here, but you're missing the speed part. Your constructor takes a double, string and then double, you only give it a double and a string.

[CrazdKC]

I'm sorry, this is flying a little over my head. Are you saying I should set the variable Speed? I though I did so by

double Speed=0

[TarikNeaj]

You're doing that inside The constructor's parameters. It's not exactly what you think it is. That constructor is made so that you will send in 3 values to it, and it will give those values to your private variables.

Car::Car(double YearModel, string Make, double Speed = 0)

This constructor takes 3 values as you can see for yourself. Your problem is that you're only sending in to 2 out of 3 Car myCar(YearModel, Make); you're missing the speed part.

I believe you need to ask the user for the speed. And then send it in so it looks like this

Car myCar(YearModel, Make, speed);

And inside the constructor initialize your private variables.

Car::Car(double userYearModel, string userMake, double userSpeed)
{
	Speed = userSpeed;
	YearModel = userYearModel;
	Make = userMake;
	
}

Now, all the values the user entered for the model, make and speed, is stores in the variables you created for your class

class Car
{
private:
	double YearModel;
	string Make;
	double Speed;

edit: I changed the name of the variables inside the constructor parameter so you can see things more clearly, it can be confusing when they have the same name.

[CrazdKC]

Got it! Thankyou for the help.