how to show number of digits in c++ code example

Example: c++ get digits of integer

int iNums = 12345;
int iNumsSize = 5;
for (int i=iNumsSize-1; i>=0; i--) {
    int y = pow(10, i);
    int z = iNums/y;
    int x2 = iNums / (y * 10);
    printf("%d-",z - x2*10 );
}