How do I split an int into its digits?

Question

How can I split an int in c++ to its single numbers? For example, I\'d like to split 23 to 2 and 3.

Answer 1

Declare an Array and store Individual digits to the array like this

int num, temp, digits = 0, s, td=1;
int d[10];
cout << "Enter the Number: ";
cin >> num;
temp = num;
do{
    ++digits;
    temp /= 10;
} while (temp);

for (int i = 0; i < digits-1; i++)
{
    td *= 10;
}

s = num;
for (int i = 0; i < digits; i++)
{
    d[i] = s / td %10;
    td /= 10;

}

Answer 2

You can just use a sequence of x/10.0f and std::floor operations to have "math approach". Or you can also use boost::lexical_cast(the_number) to obtain a string and then you can simply do the_string.c_str()[i] to access the individual characters (the "string approach").

Answer 3

    int power(int n, int b) {
    int number;
    number = pow(n, b);
    return number;
}


void NumberOfDigits() {
    int n, a;
    printf("Eneter number \n");
    scanf_s("%d", &n);
    int i = 0;
    do{
        i++;
    } while (n / pow(10, i) > 1);
    printf("Number of digits is: \t %d \n", i);

    for (int j = i-1; j >= 0; j--) {
        a = n / power(10, j) % 10;
        printf("%d \n", a);
    }
}

int main(void) {
    NumberOfDigits();
}

Answer 4

Reversed order digit extractor (eg. for 23 will be 3 and 2):

while (number > 0)
{
    int digit = number%10;
    number /= 10;
    //print digit
}

Normal order digit extractor (eg. for 23 will be 2 and 3):

std::stack<int> sd;

while (number > 0)
{
    int digit = number%10;
    number /= 10;
    sd.push(digit);
}

while (!sd.empty())
{
    int digit = sd.top();
    sd.pop();
    //print digit
}

Answer 5

I don't necessarily recommend this (it's more efficient to work with the number rather than converting it to a string), but it's easy and it works :)

#include <algorithm>
#include <iostream>
#include <iterator>
#include <string>

#include <boost/lexical_cast.hpp>

int main()
{
    int n = 23984;
    std::string s = boost::lexical_cast<std::string>(n);
    std::copy(s.begin(), s.end(), std::ostream_iterator<char>(std::cout, "\n"));
    return 0;
}

Answer 6

Given the number 12345 :

5 is 12345 % 10
4 is 12345 / 10 % 10
3 is 12345 / 100 % 10
2 is 12345 / 1000 % 10
1 is 12345 / 10000 % 10

I won't provide a complete code as this surely looks like homework, but I'm sure you get the pattern.