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

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

#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

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