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constexprbool empty()constnoexcept; | (since C++17) | |
Checks if the view has no characters, i.e. whethersize()==0.
Contents |
(none)
true if the view is empty,false otherwise.
Constant.
#include <iostream>#include <string_view> // Print a string surrounded by single quotes, its// length and whether it is considered empty.void check_string(std::string_view ref){std::cout<<std::boolalpha<<"'"<< ref<<"' has "<< ref.size()<<" character(s); emptiness: "<< ref.empty()<<'\n';} int main(int argc,char**argv){// An empty string check_string(""); // Almost always not empty: argv[0]if(argc>0) check_string(argv[0]);}
Possible output:
'' has 0 character(s); emptiness: true'./a.out' has 7 character(s); emptiness: false
| returns the number of characters (public member function)[edit] | |
| returns the maximum number of characters (public member function)[edit] | |
(C++17)(C++20) | returns the size of a container or array (function template)[edit] |
(C++17) | checks whether the container is empty (function template)[edit] |
| checks whether the string is empty (public member function of std::basic_string<CharT,Traits,Allocator>)[edit] |
