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

 

C++

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Named requirements

Feature test macros (C++20)

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Concepts library (C++20)

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Containers library

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Symbols index

External libraries

 

Strings library

Null-terminated strings

Byte strings

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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) 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*) 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

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void pop_back();		(constexpr since C++20)

Removes the last character from the string.

Equivalent to erase(end() - 1). The behavior is undefined if the string is empty.

Parameters

(none)

Return value

(none)

Complexity

Constant.

Exceptions

Throws nothing.

Notes

In libstdc++, pop_back() is not available in C++98 mode.

Example

Run this code

#include <cassert>
#include <iomanip>
#include <iostream>
#include <string>
 
int main()
{
    std::string str("Short string!");
    std::cout << "Before: " << std::quoted(str) << '\n';
    assert(str.size() == 13);
 
    str.pop_back();
    std::cout << "After:  " << std::quoted(str) << '\n';
    assert(str.size() == 12);
 
    str.clear();
//  str.pop_back(); // undefined behavior
}

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 534	C++98	std::basic_string did not have the member function pop_back()	added

See also

push_back	appends a character to the end (public member function)
erase	removes characters (public member function)