std::basic_string<CharT,Traits,Allocator>:: erase

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basic_string::erase
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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.

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
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)
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