C++ get each digit in int

Question

I have an integer:

int iNums = 12476;

And now I want to get each digit from iNums as integer. Something like:

foreach(iNum          


        

Answer 1

Here is a more generic though recursive solution that yields a vector of digits:

void collect_digits(std::vector<int>& digits, unsigned long num) {
    if (num > 9) {
        collect_digits(digits, num / 10);
    }
    digits.push_back(num % 10);
}

Being that there are is a relatively small number of digits, the recursion is neatly bounded.

Answer 2

I know this is an old post, but all of these answers were unacceptable to me, so I wrote my own!

My purpose was for rendering a number to a screen, hence the function names.

void RenderNumber(int to_print)
{
    if (to_print < 0)
    {
        RenderMinusSign()
        RenderNumber(-to_print);
    }
    else
    {
        int digits = 1; // Assume if 0 is entered we want to print 0 (i.e. minimum of 1 digit)
        int max = 10;

        while (to_print >= max) // find how many digits the number is 
        {
            max *= 10;
            digits ++;
        }

        for (int i = 0; i < digits; i++) // loop through each digit
        {
            max /= 10;
            int num = to_print / max; // isolate first digit
            to_print -= num * max; // subtract first digit from number
            RenderDigit(num);
        }
    }
}

Answer 3

The answer I've used is this simple function:

int getDigit(int n, int position) {

    return (n%(int)pow(10, position) - (n % (int)pow(10, position-1))) / (int)pow(10, position-1);

}

Hope someone finds this helpful!

Answer 4

I don't know if this is faster or slower or worthless, but this would be an alternative:

int iNums = 12476;
string numString;
stringstream ss;
ss << iNums;
numString = ss.str();
for (int i = 0; i < numString.length(); i++) {
    int myInt = static_cast<int>(numString[i] - '0'); // '0' = 48
    printf("%i-", myInt);
}

I point this out as iNums alludes to possibly being user input, and if the user input was a string in the first place you wouldn't need to go through the hassle of converting the int to a string.

(to_string could be used in c++11)

Answer 5

Drawn from D.Shawley's answer, can go a bit further to completely answer by outputing the result:

void stream_digits(std::ostream& output, int num, const std::string& delimiter = "")
{
    if (num) {
        stream_digits(output, num/10, delimiter);
        output << static_cast<char>('0' + (num % 10)) << delimiter;
    }
}

void splitDigits()
{
    int num = 12476;    
    stream_digits(std::cout, num, "-");    
    std::cout << std::endl;
}

Answer 6

Based on @Abyx's answer, but uses div so that only 1 division is done per digit.

#include <cstdlib>
#include <iostream>

void print_each_digit(int x)
{
    div_t q = div(x, 10);

    if (q.quot)
        print_each_digit(q.quot);

    std::cout << q.rem << '-';
}

int main()
{
    print_each_digit(12476);
    std::cout << std::endl;
    return 0;
}

Output:

1-2-4-7-6-

N.B. Only works for non-negative ints.