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

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

#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

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

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