NAME¶

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

Synopsis¶

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