NAME¶

std::basic_string::empty - std::basic_string::empty

Synopsis¶

bool empty() const; (until C++11)
bool empty() const noexcept; (since C++11)
(until C++20)
[[nodiscard]] constexpr bool empty() const noexcept; (since C++20)

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

Parameters¶

(none)

Return value¶

true if the string is empty, false otherwise

Complexity¶

Constant.

Example¶

// Run this code

#include <iostream>
#include <string>

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:''

See also¶

size returns the number of characters
length (public member function)
max_size returns the maximum number of characters
(public member function)
returns the number of characters that can be held in currently allocated
capacity storage
(public member function)
size
ssize returns the size of a container or array
(C++17) (function template)
(C++20)
empty checks whether the container is empty
(C++17) (function template)
empty checks whether the view is empty
(C++17) (public member function of std::basic_string_view<CharT,Traits>)