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

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

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)
checks whether the view is empty
(public member function of std::basic_string_view<CharT,Traits> )
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