Movatterモバイル変換


[0]ホーム

URL:


cppreference.com
Namespaces
Variants
    Actions

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

      From cppreference.com
      <cpp‎ |string‎ |basic string
       
       
       
      std::basic_string
       
      void clear();
      (noexcept since C++11)
      (constexpr since C++20)

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

      All pointers, references, and iterators are invalidated.

      Contents

      [edit]Parameters

      (none)

      [edit]Return value

      (none)

      [edit]Notes

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

      [edit]Complexity

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

      [edit]Example

      Run this code
      #include <cassert>#include <iostream>#include <string> int main(){std::string s{"Exemplar"};    std::string::size_typeconst capacity= s.capacity();     s.clear();assert(s.empty());assert(s.size()==0);std::cout<<std::boolalpha<<(s.capacity()== capacity)<<'\n';}

      Possible output:

      true

      [edit]See also

      removes characters
      (public member function)[edit]
      Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/string/basic_string/clear&oldid=177141"

      [8]ページ先頭

      ©2009-2025 Movatter.jp