How do I remove a character from a string in c++? - c++

Question

I need help debugging my code. I've tried many things, but I can't seem to be able to delete a character from a string.
I also don't understand completely how std::erase works, I'm not sure if you can erase characters with it.
#include <iostream>
#include <string>
using namespace std;
int main(){
string s;
char n;
cin >> s;
cin >> n;
for (int i = 0;i < s.length(); i++) {
s.erase (n[i]);
}
cout << s;
return 0;
}
EDIT: Sorry for being so vague. I recognized my issue of attempting to delete something from an array rather than the intended string. With the help of the answers posted; the updated code is attached below that works the way I want it to. Thank you for your responses!
#include <iostream>
#include <string>
using namespace std;
int main(){
string s;
char n;
cin >> s;
cin >> n;
for (int i = 0; i < s.length(); i++) {
while (s[i] == n) {
s.erase(i, i);
}
}
cout << s;
return 0;
}

Answer 1

Use the erase-remove idiom:
#include <iostream>
#include <string>
#include <algorithm>
int main() {
std::string s = "Hello World!";
s.erase(std::remove(s.begin(), s.end(), 'l', s.end());
std::cout << s << std::endl;
return 0;
}
Broken down into two statements it would be:
#include <iostream>
#include <string>
#include <algorithm>
int main() {
std::string s = "Hello World!";
auto it = std::remove(s.begin(), s.end(), 'l');
s.erase(it, s.end());
std::cout << s << std::endl;
return 0;
}

Answer 2

If you want just to remove one character from the string you can use its method find to find the character in the string. For example
auto pos = s.find( n );
if ( pos != std::string::npos ) s.erase( pos, 1 );
Or you can use a loop the following way
std::string::size_type pos = 0;
while ( pos < s.size() && s[pos] != n ) ++pos;
if ( pos != s.size() ) s.erase( pos, 1 );
If you want to erase all occurrences of the character in the string using a loop you can write
for ( std::string::size_type pos = 0; pos < s.size(); )
{
if ( s[pos] == n ) s.erase( pos, 1 );
else ++pos;
}

Answer 3

It will be helpful if you included a proper description of what you are trying to do. The question is a little vague but I presume you are trying to remove a given char from a string, if that's what you are trying to do, here is a working example that builds on what you already provided.
#include <iostream>
#include <string>
using namespace std;
int main(){
string s;
char n ;
cin >> s;
cin >> n;
for (int i = 0; i < s.length(); i++) {
if (s[i] == n) {
s.erase(i, 1);
}
}
cout << s;
return 0;
}