std::basic_string<CharT,Traits,Allocator>::empty
< cpp | string | basic string
bool empty() const; |
(until C++11) | |
bool empty() const noexcept; |
(since C++11) (until C++20) |
|
[[nodiscard]] 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
returns the number of characters (public member function) |