Question

How to use and initialize array of classes in C++

Answer 1

#include <iostream>

using std::cout;
using std::endl;

class Box {
public:
	Box(double _length, double _width = 1.0, double _height = 1.0) :
		length(_length),
		width(_width),
		height(_height)
	{}
	Box() 	{
		length = width = height = 1.0;
	}

	void Print() 
	{
		cout << length << " " << width << " " << height << endl;
	}	
	double Volume() const
	{
		return length * width * height;
	}
private:
	double length;
	double width;
	double height;
};

int main()
{
	Box arr[3]
	{
		Box(1, 2, 3),
		Box(2, 4, 6),
		Box(1.2, 3.5, 6.7)
	};

	arr[0].Print();
	arr[1].Print();
	arr[2].Print();

	cout << arr[0].Volume() << endl;
	cout << arr[1].Volume() << endl;
	cout << arr[2].Volume() << endl;
	
	return 0;
}


/*
run:

1 2 3
2 4 6
1.2 3.5 6.7
6
48
28.14

*/

 

70+ SQL courses for beginners and professionals

Answer 2

#include <iostream>

using std::cout;
using std::endl;

class Box {
public:
	Box(double _length, double _width = 1.0, double _height = 1.0) :
		length(_length),
		width(_width),
		height(_height)
	{}
	Box() 	{
		length = width = height = 3.0;
	}

	void Print() 
	{
		cout << length << " " << width << " " << height << endl;
	}	
	double Volume() const
	{
		return length * width * height;
	}
private:
	double length;
	double width;
	double height;
};

int main()
{
	Box arr[2];

	arr[0].Print();
	arr[1].Print();

	cout << arr[0].Volume() << endl;
	cout << arr[1].Volume() << endl;
	
	return 0;
}


/*
run:

3 3 3
3 3 3
27
27

*/

 

70+ SQL courses for beginners and professionals