std::basic_string_view<CharT,Traits>::size, std::basic_string_view<CharT,Traits>::length

constexpr size_type size() const noexcept;
 (since C++17) 
constexpr size_type length() const noexcept;
 (since C++17)

Returns the number of CharT elements in the view, i.e. std::distance(begin(), end()).

Parameters

(none).

Return value

The number of CharT elements in the view.

Complexity

Constant.

Example

#include <string_view>
#include <iostream>
 
void check_string(std::string_view ref)
{
        // Print a string surrounded by single quotes, its length
        // and whether it is considered empty.
        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

See also

checks whether the view is empty
(public member function)
returns the maximum number of characters
(public member function)

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