std::basic_string<CharT,Traits,Allocator>::empty - cppreference.com (original) (raw)

| bool empty() const; | | (noexcept since C++11) (constexpr since C++20) | | ------------------- | | ---------------------------------------------- |

Checks if the string has no characters, i.e. whether begin() == end().

[edit] Parameters

(none)

[edit] Return value

true if the string is empty, false otherwise

[edit] Complexity

Constant.

[edit] Example

#include #include   int main() { std::string s; std::boolalpha(std::cout); std::cout << "s.empty():" << s.empty() << "\t s:'" << s << "'\n";   s = "Exemplar"; std::cout << "s.empty():" << s.empty() << "\t s:'" << s << "'\n";   s = ""; std::cout << "s.empty():" << s.empty() << "\t s:'" << s << "'\n"; }

Output:

s.empty():true s:'' s.empty():false s:'Exemplar' s.empty():true s:''

[edit] See also