Having issues converting numbers into roman numerals - c++

Question

for class I have to create a code so that it could ask the user for an integer between 1-99 and be able to print that integer in roman numerals. Issue is after creating my code it would only print the numbers fully up to 39. Once it hits 40 it give's no Roman Numeral output and then from 41-99 it wont print the tenth place value(Ex. 45 will come out as V). Here's my code at the moment.
#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
int main()
{
int num;
int tenum;
int remnum;
string romnum;
string fromnum;
cout << "Enter a number between 1 and 99. \n";
cin >> num;
tenum = num / 10;
remnum = num % 10;
if (tenum == 9)
{
fromnum == "XC";
}
else if (tenum == 8)
{
fromnum == "LXXX";
}
else if (tenum == 7)
{
fromnum == "LXX";
}
else if (tenum == 6)
{
fromnum == "LX";
}
else if (tenum == 5)
{
fromnum == "L";
}
else if (tenum == 4)
{
fromnum == "XL";
}
else if (tenum == 3)
{
fromnum = "XXX";
}
else if (tenum == 2)
{
fromnum == "XX";
}
else if (tenum == 1)
{
fromnum == "X";
}
if (remnum == 9)
{
romnum = "IX";
}
else if (remnum == 8)
{
romnum = "VIII";
}
else if (remnum == 7)
{
romnum = "VII";
}
else if (remnum == 6)
{
romnum = "VI";
}
else if (remnum == 5)
{
romnum = "V";
}
else if (remnum == 4)
{
romnum = "IV";
}
else if (remnum == 3)
{
romnum = "III";
}
else if (remnum == 2)
{
romnum = "II";
}
else if (remnum == 1)
{
romnum = "I";
}
cout << tenum << endl;
cout << remnum << endl;
cout << fromnum;
cout << romnum << endl;
return 0;
}

Answer 1

You've mixed up == and =
change lines like
fromnum == "XL"
to
fromnum = "XL"
Demo
(I used a switch statement for brevity)

Answer 2

same answer with: Converting integer to Roman Numeral
#include <iostream>
#include <string>
std::string to_roman(int value)
{
struct romandata_t { int value; char const* numeral; };
static romandata_t const romandata[] =
{ 1000, "M",
900, "CM",
500, "D",
400, "CD",
100, "C",
90, "XC",
50, "L",
40, "XL",
10, "X",
9, "IX",
5, "V",
4, "IV",
1, "I",
0, NULL }; // end marker
std::string result;
for (romandata_t const* current = romandata; current->value > 0; ++current)
{
while (value >= current->value)
{
result += current->numeral;
value -= current->value;
}
}
return result;
}
int main()
{
for (int i = 1; i <= 4000; ++i)
{
std::cout << to_roman(i) << std::endl;
}
}
this code converts up to 1000. just take what you need and you are good to go!
from http://rosettacode.org/wiki/Roman_numerals/Encode#C.2B.2B