Removing items from vector string C++ - c++

Question

I have a vector, it's contents are like so..
std::vector<string> vec;
vec.push_back("XXXX_LLLL");
vec.push_back("XXXX_HHHH");
vec.push_back("XXXX_XXXX");
I'd like to iterate over the vector and remove the "_" from the string. I've tried using the find-erase idiom as so, with a struct I made to find _.
vec.erase(remove_if(vec.begin(), vec.end(), IsUnderScore2()),vec.end());
But I realized it's not iterating over each individual string in my vector string, so it will never erase the underscore. Is there another method of iterating over a vector, and it's individual components, that can help me here?

Answer 1

Iterate through the vector and use the erase-remove idiom on each string, instead of on the vector elements as you're doing right now
std::vector<string> vec;
vec.push_back("XXXX_LLLL");
vec.push_back("XXXX_HHHH");
vec.push_back("XXXX_XXXX");
for(auto& str : vec) {
str.erase(std::remove(str.begin(), str.end(), '_'),
str.end());
}
C++03 version:
for(std::vector<std::string>::iterator it = vec.begin(), it != vec.end(), ++it) {
it->erase(std::remove(it->begin(), it->end(), '_'),
it->end());
}

Answer 2

Try the following. You can use standard algorithm std::remove applied to each string of the vector.
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
int main()
{
std::vector<std::string> vec;
vec.push_back("XXXX_LLLL");
vec.push_back("XXXX_HHHH");
vec.push_back("XXXX_XXXX");
for ( std::string &s : vec )
{
s.erase( std::remove( s.begin(), s.end(), '_'), s.end() );
}
for ( const std::string &s : vec ) std::cout << s << std::endl;
return 0;
}
The output is
XXXXLLLL
XXXXHHHH
XXXXXXXX
If your compiler does not support the C++ 2011 then you can write
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
int main()
{
std::vector<std::string> vec;
vec.push_back("XXXX_LLLL");
vec.push_back("XXXX_HHHH");
vec.push_back("XXXX_XXXX");
for (std::vector<std::string>::iterator it = vec.begin(); it != vec.end(); ++it )
{
it->erase( std::remove( it->begin(), it->end(), '_'), it->end() );
}
for (std::vector<std::string>::iterator it = vec.begin(); it != vec.end(); ++it )
{
std::cout << *it << std::endl;
}
return 0;
}

Answer 3

Using regular expressions would look like :
for_each(vec.begin(), vec.end(), [&](string &str) {
regex_replace(str.begin(), str.begin(), str.end(), regex("_"), "");
});
Demo
A range based for loop version might be more readable :
for(auto &str : vec) {
regex_replace(str.begin(), str.begin(), str.end(), regex("_"), "");
}