Removing all occurrences of a character from a string in C++ - c++

Question

My assignment says I should write a function called removeChar that;
Takes 4 inputs: an integer num, a string str, a string s and a character c, but does not return
anything.
Finds the number of all the occurrences of c in s (both capital and lower case (hint: you may
use ASCII codes for comparison)) and saves it in num
Copies the trimmed string in str
Write in the same file a main() function containing a series of tests to showcase the correct
behavior of removeChar ().
But all printing operations should be done from the main() function. I have this code:
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
string removeChar(int num, string s, string str, char c);
int main()
{
string s = "asdfasdf";
s = removeChar(1, "a", "hello", 'h');
cout << s;
}
string removeChar(int num, string s, string str, char c)
{
int i;
for (i = 0; i < s.length(); i++)
if (int(s.at(i)) == int(c))
num = int(c);
str.erase(std::remove(str.begin(), str.end(), (char)num), str.end());
return str;
}
It doesn't work, and even if it did, I need to have a void function.

Answer 1

If I have understood the description of the assignment correctly,
then you need something like the following:
#include <iostream>
#include <string>
#include <iterator>
#include <algorithm>
#include <cctype>
void removeChar( std::string::size_type &n, std::string &str, const std::string &s, char c )
{
str.clear();
c = std::toupper( ( unsigned char )c );
auto equal_to_c = [&c]( const auto &item )
{
return std::toupper( ( unsigned char )item ) == c;
};
std::remove_copy_if( std::begin( s ), std::end( s ),
std::back_inserter( str ),
equal_to_c );
n = s.size() - str.size();
}
int main()
{
std::string::size_type n = 0;
std::string str;
removeChar( n, str, "This is a silly assignment", 's' );
std::cout << "n = " << n << ", str = " << str << '\n';
return 0;
}
The program output is:
n = 5, str = Thi i a illy aignment