Integer to string issue

[Wantedman46]

I am currently trying to change an integer to a string. I am successful in that, but I am unable to make my program's class return the string without error. It states that "no operator "[]" matches these operands. The issue is in my last "for" statement in my LargeInt.cpp, first "cout". Any suggestions?

LargeInt.h

#pragma once
class LargeInt
{
public:
	LargeInt() {};
	void ADDITION();
private:
	int Number1[255], Number2[255] , ADD[255];
	char S1[255], S2[255];
	int L1, L2;
};

  

LargeInt.cpp

#include "LargeInt.h"
#include <string>
#include <iostream>
#include "stdafx.h"

using namespace std;

void LargeInt::ADDITION()
{
	cout << "What is your first number to add? " << endl;
	cin >> S1;
	cout << "What is your second number to add? " << endl;
	cin >> S2;
	cout << endl;
	for (L1 = 0; S1[L1] != '\0'; L1++)
	{
		Number1[L1] = S1[L1] - '0';
	}
	for (L2 = 0; S2[L2] != '\0'; L2++)
	{
		Number2[L2] = S2[L2] - '0';
	}
	int carry = 0;
	int k = 0;
	int i = L1 - 1;
	int j = L2 - 1;
	string final = to_string(k);

	for (; i >= 0 && j >= 0; i--, j--, k++)
	{
		ADD[k] = (Number1[i] + Number2[j] + carry) % 10;
		carry = (Number1[i] + Number2[j] + carry) / 10;
	}

	if (L1 > L2)
	{
		while (i >= 0) {
			ADD[k++] = (Number1[i] + carry) % 10;
			carry = (Number1[i--] + carry) / 10;
		}
	}
	else if (L1 < L2)
	{
		while (j >= 0) {
			ADD[k++] = (Number2[j--] + carry) / 10;
		}
	}
	else
	{
		if (carry > 0)
			ADD[k++] = carry;
	}
	cout << "The first number you entered was: ";
	cout << S1 << endl;
	cout << "The second number you endered was: ";
	cout << S2 << endl;
	cout << "Sum of your two large numbers is = ";

	for (k--; k >= 0; k--)
	{
		cout << ADD[final] << endl;
		cout << endl;
	}
}

main.cpp

#include "stdafx.h"
#include <iostream>
#include <iomanip>
#include <string>
#include "LargeInt.h"

using namespace std;


int main()
{
	cout << endl;
	cout << "Enter a number to calculate the addtion of two large numbers" << endl;

	LargeInt digit;

	digit.ADDITION();


	cout << endl;
	system("pause");
    return 0;
}

[coder777]

I am currently trying to change an integer to a string.

There is no reason to do that. final is a string hence cannot be used as an index and will always contain "0". Why don't you use just k?

[Enoizat]

‘final’ is a reserved word:
http://en.cppreference.com/w/cpp/language/final
You can’t declare a variable named ‘final’. <-- Wrong. See Repeater’s correction below.
To create a std::string from an int array, you need to transform any ‘int’ back into a ‘char’.

Hints:

#include "LargeInt.h"
#include <string>
#include <iostream>

void LargeInt::ADDITION()
{
    std::cout << "What is your first number to add? ";
    std::cin >> S1;
    std::cout << "What is your second number to add? ";
    std::cin >> S2;
    std::cout << '\n';
    for (L1 = 0; S1[L1] != '\0'; L1++) { Number1[L1] = S1[L1] - '0'; }
    for (L2 = 0; S2[L2] != '\0'; L2++) { Number2[L2] = S2[L2] - '0'; }
    int carry = 0;
    int k = 0;
    int i = L1 - 1;
    int j = L2 - 1;

    for (; i >= 0 && j >= 0; i--, j--, k++)
    {
        ADD[k] = (Number1[i] + Number2[j] + carry) % 10;
        carry = (Number1[i] + Number2[j] + carry) / 10;
    }

    if (L1 > L2)
    {
        while (i >= 0) {
            ADD[k++] = (Number1[i] + carry) % 10;
            carry = (Number1[i--] + carry) / 10;
        }
    }
    else if (L1 < L2)
    {
        while (j >= 0) {
            ADD[k++] = (Number2[j--] + carry) / 10;
        }
    }
    else
    {
        if (carry > 0)
        ADD[k++] = carry;
    }
    std::cout <<   "The first number you entered was: "  << S1
              << "\nThe second number you entered was: " << S2
              << "\nSum of your two large numbers is = ";

    // for (k--; k >= 0; k--) { std::cout << ADD[k]; }
    // std::cout << '\n';
    std::string result;
    for (k--; k >= 0; k--) { result += ADD[k] + '0'; }
    std::cout << result << '\n';
}

[masecla33]

Not really helpful, as i can't understand your code.. but itoa should convert int to char arrays which can be converted into strings,

[Repeater]

‘final’ is a reserved word:
http://en.cppreference.com/w/cpp/language/final
You can’t declare a variable named ‘final’.

While I certainly agree it's bad form, the page you link to explicitly states that "final"

may be used to name objects and functions.

[Enoizat]

Repeater wrote:

While I certainly agree it's bad form, the page you link to explicitly states that "final"
may be used to name objects and functions.

You’re right, Repeater, I really missed that point. Thank you for your correction.
I’ve edited my previous post.