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

 

C++

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

 

Strings library

Null-terminated strings

Byte strings

Multibyte strings

Wide strings

Classes

basic_string

basic_string_view (C++17)

char_traits

 

std::basic_string

Member functions basic_string::basic_string basic_string::operator= basic_string::assign basic_string::get_allocator Element access basic_string::at basic_string::operator[] basic_string::front (C++11) basic_string::back (C++11) 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) Capacity basic_string::empty basic_string::sizebasic_string::length basic_string::max_size basic_string::reserve basic_string::capacity basic_string::shrink_to_fit (C++11)   Operations basic_string::clear basic_string::insert basic_string::erase basic_string::push_back basic_string::pop_back (C++11) basic_string::append basic_string::operator+= basic_string::compare basic_string::starts_with (C++20)   basic_string::ends_with (C++20) basic_string::contains (C++23) basic_string::replace basic_string::substr basic_string::copy basic_string::resize basic_string::resize_and_overwrite (C++23) basic_string::swap

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void push_back( CharT ch );		(until C++20)
constexpr void push_back( CharT ch );		(since C++20)

Appends the given character ch to the end of the string.

Parameters

ch

-

the character to append

Return value

(none)

Complexity

Amortized constant.

Exceptions

If an exception is thrown for any reason, this function has no effect (strong exception guarantee). (since C++11)

If the operation would result in size() > max_size(), throws std::length_error.

Example

Run this code

#include <cassert>
#include <string>
#include <iomanip>
#include <iostream>
 
int main()
{
    std::string str{"Short string"};
    std::cout << "before=" << std::quoted(str) << '\n';
    assert(str.size() == 12);
 
    str.push_back('!');
    std::cout << " after=" << quoted(str) << '\n';
    assert(str.size() == 13);
}

Output:

before="Short string"
 after="Short string!"

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 7	C++98	(1) the description was missing in the C++ standard (2) the parameter type was const CharT	(1) description added (2) changed to CharT

See also

pop_back (C++11)

removes the last character (public member function)