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std::basic_string::clear(3) C++ Standard Libary std::basic_string::clear(3)

NAME

std::basic_string::clear - std::basic_string::clear

Synopsis


void clear(); (noexcept since C++11)
(constexpr since C++20)


Removes all characters from the string as if by executing erase(begin(), end()).


All pointers, references, and iterators are invalidated.

Parameters


(none)

Return value


(none)

Notes


Unlike for std::vector::clear, the C++ standard does not explicitly require that
capacity is unchanged by this function, but existing implementations do not change
capacity. This means that they do not release the allocated memory (see also
shrink_to_fit).

Complexity


Linear in the size of the string, although existing implementations operate in
constant time.

Example

// Run this code


#include <cassert>
#include <string>


int main()
{
std::string s{"Exemplar"};
std::string::size_type const capacity = s.capacity();


s.clear();
assert(s.capacity() == capacity); // <- not guaranteed
assert(s.empty());
assert(s.size() == 0);
}

See also


erase removes characters
(public member function)

2024.06.10 http://cppreference.com