Need help with commas in calc program

[jDurks619]

While perfecting and adding things to my first calculator program i ever wrote, i have all the basic things and now, I'm left to wonder how to make numbers like 34293 into 34,293 and add commas every 3rd number.

This is just a section of my program that raises a given number to a given power.

                                       unsigned int x, power;
                                       unsigned long int product;

					cout << "Pick a number you wish to raise to the power of another number: ";
					cin >> x;
					
					cout << endl << endl;

					cout << "Pick a number you wish to be the \n";
					cout << "amount times the first number is multipled by: ";
					cin >> power;

					cout << endl << endl;

					product = pow(x, power);
					
					cout << x << " rasied to the power of " << power << " equals " << product << "." << endl << endl;

					cout << "Press Y if you want to return to the ";
					cout << "main menu, Press N if u want to close the program: ";
					cin >> repeatMenu;
					break;

[Stalker]

The answer is to ignore the comma. You can take the number in a string format with all the comas. Then when you are reading the string from the user you can skip input whenever a coma is an input. Then once you have the whole number in string format you can use the string to number conversion functions like stod and stoi.

[jDurks619]

I finally found some source code that actually works and put commas in but after the program stops it pops up, unhandled exception, the string binding is invalid. heres the code

template<typename CharT>
struct Sep : public std::numpunct<CharT>
{
	virtual std::string do_grouping()      const   { return "\003"; }
};

int main()
{
	std::cout.imbue(std::locale(std::cout.getloc(), new Sep <char>()));

	std::cout << 123456789 << "\n";

and i use it with #include <locale> ofc.

[TheIdeasMan]

Try this one, from JLBorges

http://www.cplusplus.com/forum/general/71848/#msg383107

[integralfx]

How about this?
https://ideone.com/3N8PvS

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

string toString(const int num)
{
	stringstream ss;
	ss << num;
	return ss.str();
}

void formatCommas(string& str)
{
	/*
	we add a comma every 3rd digit
	*/
	int num_of_commas = str.length() / 3;
	/*
	we don't want a comma at the end of temp
	eg. 133 333 337
	num_of_commas = 3
	but there only should be 2 commas.
	*/
	if(str.length() % 3 == 0) --num_of_commas;
	/*
	reverse the string to make it easier to work with
	this is because we start adding commas from the end
	*/
	string temp(str.rbegin(), str.rend());
	/*
	add the commas in the necessary position, i.e. every 3rd digit
	note the i-1. this is because the length of the string changed
	due to us adding a comma so we need to compensate for that.
	*/
	for(int i{1}; i <= num_of_commas; i++) {
		temp.insert(i * 3 + i-1, ",");
	}
	/*
	reverse the reversed string to put the string in order
	*/
	str.assign(temp.rbegin(), temp.rend());
}

int main()
{
	int num{ 133333337 };
	cout << "Original number: " << num << "\n";
	string strNum{ toString(num) };
	formatCommas(strNum);
	cout << "Formatted number: " + strNum + "\n";
}

Original number: 133333337
Formatted number: 133,333,337