std::basic_string<CharT,Traits,Allocator>::erase
From cppreference.com
< cpp | string | basic string
basic_string& erase( size_type index = 0, size_type count = npos ); |
(1) | (constexpr since C++20) |
(2) | ||
iterator erase( iterator position ); |
(until C++11) | |
iterator erase( const_iterator position ); |
(since C++11) (constexpr since C++20) |
|
(3) | ||
iterator erase( iterator first, iterator last ); |
(until C++11) | |
iterator erase( const_iterator first, const_iterator last ); |
(since C++11) (constexpr since C++20) |
|
Removes specified characters from the string.
2) Removes the character at position.
3) Removes the characters in the range
[
first,
last)
. If first or last is not a valid iterator on *this, or
[
first,
last)
is not a valid range, the behavior is undefined.Parameters
index | - | first character to remove |
count | - | number of characters to remove |
position | - | iterator to the character to remove |
first, last | - | range of the characters to remove |
Return value
1) *this
2) Iterator pointing to the character immediately following the character erased, or end() if no such character exists.
3) Iterator pointing to the character last pointed to before the erase, or end() if no such character exists.
Exceptions
2,3) Throws nothing.
If an exception is thrown for any reason, this function has no effect (strong exception safety guarantee).
Example
Run this code
#include <algorithm> #include <iostream> #include <iterator> #include <string> int main() { std::string s = "This Is An Example"; std::cout << "1) " << s << '\n'; s.erase(7, 3); // erases " An" using overload (1) std::cout << "2) " << s << '\n'; s.erase(std::find(s.begin(), s.end(), ' ')); // erases first ' '; overload (2) std::cout << "3) " << s << '\n'; s.erase(s.find(' ')); // trims from ' ' to the end of the string; overload (1) std::cout << "4) " << s << '\n'; auto it = std::next(s.begin(), s.find('s')); // obtains iterator to the first 's' s.erase(it, std::next(it, 2)); // erases "sI"; overload (3) std::cout << "5) " << s << '\n'; }
Output:
1) This Is An Example 2) This Is Example 3) ThisIs Example 4) ThisIs 5) This
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR | Applied to | Behavior as published | Correct behavior |
---|---|---|---|
LWG 27 | C++98 | overload (3) did not erase the character last pointed to, but it returned the iterator pointing to the character immediately following that character |
returns an iterator pointing to that character |
LWG 428 | C++98 | overload (2) explicitly required position to be valid, but SequenceContainer requires it to be dereferenceable (stricter) |
removed the explicit requirement |
LWG 847 | C++98 | there was no exception safety guarantee | added strong exception safety guarantee |
See also
clears the contents (public member function) |