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

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

Compiler support
Freestanding and hosted
Language
Standard library
Standard library headers
Named requirements
Feature test macros (C++20)
Language support library
Concepts library (C++20)
Metaprogramming library (C++11)
Diagnostics library
General utilities library
Strings library
Containers library
Iterators library
Ranges library (C++20)
Algorithms library
Numerics library
Localizations library
Input/output library
Filesystem library (C++17)
Regular expressions library (C++11)
Concurrency support library (C++11)
Technical specifications
Symbols index
External libraries

Null-terminated strings
Byte strings
Multibyte strings
Wide strings
Classes
basic_string
basic_string_view (C++17)
char_traits