Two-D array delete/pointer error?

[rabster]

I'm unable to delete my 2-D runtime array for some odd reason? Whenever I try to apparently I get an invalid pointer error, and something about size error whenever I put in a value greater than or equal to 5 for either the col and rows and then try to delete them with the destructor. Thus once I got rid of deleting the array (which I know is not a good thing because its going to take memory) it worked fine. Soo yeah how can I delete my array within the destructor without getting this error?

#include <iostream>
#include <climits>

using namespace std;
struct a1 {
private:
	int* x;
	int bytes;
	int go;
	int counter;
public:
	int& operator [] (int index) {
		return x[index];
	}
	a1(int a);
	~a1();
	void give() {
		for (int i = 0; i < go; i++) {
			cout << x[i];
		}
		cout << endl;
		cout << "Your array is " << bytes << "Bytes\n";
	}

};
a1::a1(int a) {
	cout << "Constructing the array ";
	x = new int[a];
	go = a;
	bytes = a * sizeof(x[0]);
	for (int i = 0; i < a; i++) {
		x[i] = 0;
	}
}
a1::~a1() {
	cout << "Destroying the array ";
	delete[] x;
}
struct a2 {
private:
	char **coL;
	char *row;
	char myC;
	int nC;
	int nR;
	int bytes;
	int sT;
public:
	a2(int ROW, int COL, char pCH);
	~a2();
	void getArray() {
                //Displays the array and sets the value as well.
		for (int z = 0; z < nC; z++) {
			sT++;
			for (int i = 0; i < nR; i++) {
				coL[z][i] = myC;
				cout << coL[z][i];
				if (i == (nR - 1)) {
					cout << endl;
				}
			}
		}
		cout << "Your array holds " << (bytes)<< "Bytes";
	}

};
a2::a2(int ROW, int COL, char pCH) {
       //Catches if user enters in 0 or a negative number for the two-D array.
	try {
		if (ROW < 0) {
			throw 1;
		}
		else if (COL < 0) {
			throw 2;
		}
		else if (COL < 0 && ROW < 0) {
			throw 3;
		}
		else if (COL == 0 || ROW == 0) {
			throw 4;
		}
		
	}
	catch (int x) {
		if (x == 1 || x == 2 || x == 3) {
			cout << "Cannot initialize an array with a negative value ";
		}
		else
			cout << "Arrays can not hold 0/NO values ";
	}
                //Sets the two-D array's values.
		sT = 0;
		nC = ROW;
		nR = COL;
		row = new char(ROW * COL);
		coL = new char*[ROW];
		myC = pCH;
		bytes = (sizeof(ROW) * (ROW * COL) / 4);
		for (int i = 0; i < ROW; ++i) {
			coL[i] = row + (COL * i);
		}
}

a2::~a2() {
	cout << "\tDestroying twoD array " << endl;
	//delete[] row;
	//delete[] coL;
}
int main() {
	char response;
	char myC;
	int pChoice;
	int a, b;
	bool stay = true;
	while (stay == true) {
		cout << "Would you like a 2-D array or 1-D array " << endl;
		cin >> pChoice;
		if (pChoice == 1) {
			cout << "How many values would you like your array to store? " << endl;
			cin >> a;
			b = a - 1;
			a1 k(a);
			k.give();
		}
		else if (pChoice == 2) {
			cout << "What kind of grid would you like? " << endl;
			cin >> a >> b;
			cout << "What kind of characters would you like your grid to be ";
			cin >> myC;
			cin.ignore(1000, '\n');
			a2 G(a, b, myC);
			G.getArray();
		}
		else {
			cout << "Not a valid choice" << endl;
			cin.clear();
			cin.ignore(1000, '\n');
			continue;
		}
	}
	cin >> response;
	return 0;
}

[Thomas1965]

It's very simple. In the constructor of a2 you only allocate the memory (in the catch block) when the user enters 0 or negative number.
What is the point in throwing an exception when you catch it there as well?

BTW. If this sth. serious or do you just try a few things?

[rabster]

I got it and I just like trying to do some thing and learn things. I'm inexperienced with exceptions so where should I catch it once thrown?

#include <iostream>
#include <climits>

using namespace std;
struct a1 {
private:
	int* x;
	int bytes;
	int go;
	int counter;
public:
	int& operator [] (int index) {
		return x[index];
	}
	a1(int a);
	~a1();
	void give() {
		for (int i = 0; i < go; i++) {
			cout << x[i];
		}
		cout << endl;
		cout << "Your array is " << bytes << "Bytes\n";
	}

};
a1::a1(int a) {
	cout << "Constructing the array ";
	x = new int[a];
	go = a;
	bytes = a * sizeof(x[0]);
	for (int i = 0; i < a; i++) {
		x[i] = 0;
	}
}
a1::~a1() {
	cout << "Destroying the array ";
	delete[] x;
}
struct a2 {
private:
	char** row;
	char* col;
	char myC;
	int nC;
	int nR;
	int bytes;
	int sT;
public:
	a2(int ROW, int COL, char pCH);
	~a2();
	void getArray() {
		for (int z = 0; z < nC; z++) {
			sT++;
			for (int i = 0; i < nR; i++) {
				row[z][i] = myC;
				cout << row[z][i];
				if (i == (nR - 1)) {
					cout << endl;
				}
			}
		}
		cout << "Your array holds " << (bytes)<< "Bytes";
	}

};
a2::a2(int ROW, int COL, char pCH) {
	try {
		if (ROW < 0) {
			throw 1;
		}
		else if (ROW < 0) {
			throw 2;
		}
		else if (ROW < 0 && COL < 0) {
			throw 3;
		}
		else if (COL == 0 || ROW == 0) {
			throw 4;
		}
		
	}
	catch (int x) {
		if (x == 1 || x == 2 || x == 3) {
			cout << "Cannot initialize an array with a negative value ";
		}
		else
			cout << "Arrays can not hold 0/NO values ";
	}
		sT = 0;
		nC = ROW;
		nR = COL;
		col = new char[ROW*COL];
                row = new char*[ROW];
                for (int i = 0; i < ROW; ++i)
    	 	row[i] = col + COL*i;
		myC = pCH;
		bytes = (sizeof(ROW) * (COL * ROW) / 4);
}

a2::~a2() {
	cout << "\tDestroying twoD array " << endl;
	delete[] row;
	delete[] col;
}
int main() {
	char response;
	char myC;
	int pChoice;
	int a, b;
	bool stay = true;
	while (stay == true) {
		cout << "Would you like a 2-D array or 1-D array " << endl;
		cin >> pChoice;
		if (pChoice == 1) {
			cout << "How many values would you like your array to store? " << endl;
			cin >> a;
			b = a - 1;
			a1 k(a);
			k.give();
		}
		else if (pChoice == 2) {
			cout << "What kind of grid would you like? " << endl;
			cin >> a >> b;
			cout << "What kind of characters would you like your grid to be ";
			cin >> myC;
			cin.ignore(1000, '\n');
			a2 G(a, b, myC);
			G.getArray();
		}
		else {
			cout << "Not a valid choice" << endl;
			cin.clear();
			cin.ignore(1000, '\n');
			continue;
		}
	}
	cin >> response;
	return 0;
}

[Thomas1965]

It depends a bit on the application where you catch and handle an exception.
As a rule of thumb you catch an exception in the code that calls the exception throwing code code.
In this case it is main().