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

 

C++

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Feature test macros (C++20)

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Concepts library (C++20)

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Technical specifications

Symbols index

External libraries

 

Strings library

Classes

basic_string

basic_string_view (C++17)

char_traits

 

std::basic_string

Member functions basic_string::basic_string basic_string::~basic_string basic_string::operator= basic_string::assign basic_string::assign_range (C++23)   basic_string::get_allocator Element access basic_string::at basic_string::operator[] basic_string::front (DR*) basic_string::back (DR*) basic_string::data basic_string::c_str basic_string::operator  basic_string_view (C++17) Iterators basic_string::beginbasic_string::cbegin (C++11) basic_string::endbasic_string::cend (C++11) basic_string::rbeginbasic_string::crbegin (C++11) basic_string::rendbasic_string::crend (C++11) Search basic_string::find basic_string::rfind basic_string::find_first_of basic_string::find_first_not_of basic_string::find_last_of basic_string::find_last_not_of

Modifiers basic_string::clear basic_string::insert basic_string::insert_range (C++23) basic_string::erase basic_string::push_back basic_string::pop_back (DR*) basic_string::append basic_string::append_range (C++23) basic_string::operator+= basic_string::replace basic_string::replace_with_range (C++23) basic_string::copy basic_string::resize basic_string::resize_and_overwrite (C++23)  basic_string::swap Capacity basic_string::empty basic_string::sizebasic_string::length basic_string::max_size basic_string::reserve basic_string::capacity basic_string::shrink_to_fit (DR*) Operations basic_string::compare basic_string::starts_with (C++20) basic_string::ends_with (C++20) basic_string::contains (C++23) basic_string::substr

Constants basic_string::npos Non-member functions operator+ swap(std::basic_string) erase(std::basic_string)erase_if(std::basic_string) (C++20)(C++20) I/O operator<<operator>> getline Comparison operator==operator!=operator<operator>operator<=operator>=operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20) Numeric conversions stoistolstoll (C++11)(C++11)(C++11) stoulstoull (C++11)(C++11)  stofstodstold (C++11)(C++11)(C++11) to_string (C++11) to_wstring (C++11) Literals operator""s (C++14) Helper classes hash<std::basic_string> (C++11) Deduction guides (C++17)

 

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

clear

clears the contents (public member function)