Erasing characters from string

Question

Please can anyone tell me how did this work?

#include<iostream>
#include<algorithm>

using namespace std;
main() {
string my_str = "ABAABACCABA";

cout << "Initial string: " << my_str << endl;

my_str.erase(remove(my_str.begin(), my_str.end(), 'A'), my_str.end()); //remove A from string
cout << "Final string: " << my_str;
}

Answer 1

std::remove() does not remove the value, but shift values. Value that's not going to be removed is shift to left, the other is right. It returns an iterator to the element that follows the last element not to be removed.

std::remove() can be used in any containers. In your case, string for example:

Original: ABAABACCABA
std::remove(): BBCCBAAAAA
iterator ^

string::erase() erases a position (1 iterator or value) or a range (2 iterators) from a string. If for the start iterator, we use the iterator std::remove() returns, and the second use std::string::end(), then

BBCCBAAAAA
^ ^ ^ ^ ^
will be removed.