NAME¶

std::basic_string::erase - std::basic_string::erase

Synopsis¶

basic_string& erase( (constexpr since
size_type index = 0, (1) C++20)
size_type count = npos );
iterator erase( iterator (until C++11)
position );
iterator erase( (since C++11)
const_iterator position ); (constexpr since
(2) C++20)
iterator erase( iterator (until C++11)
first, iterator last );
iterator erase( (3) (since C++11)
const_iterator first, (constexpr since
const_iterator last ); C++20)

Removes specified characters from the string.

1) Removes std::min(count, size() - index) characters starting at index.
2) Removes the character at position.
If position is not a dereferenceable iterator on *this, the behavior is undefined.
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¶

1) std::out_of_range if index > size().
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
overload (3) did not erase the character returns an iterator
LWG 27 C++98 last pointed to, but it returned pointing to that
the iterator pointing to the character character
immediately following that character
overload (2) explicitly required position
LWG 428 C++98 to be valid, but removed the
SequenceContainer requires it to be explicit requirement
dereferenceable (stricter)
LWG 847 C++98 there was no exception safety guarantee added strong exception
safety guarantee

See also¶

clear clears the contents
(public member function)