std::char_traits<char>::length, std::char_traits<wchar_t>::length, std::char_traits<char8_t>::length, std::char_traits<char16_t>::length, std::char_traits<char32_t>::length
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< cpp | string | char traits
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static std::size_t length( const char_type* s );
(constexpr since C++17)
Returns the length of the character sequence pointed to by s, that is, the position of the terminating null character (char_type()).
See CharTraits for the general requirements on character traits for X::length.
Contents
[edit] Parameters
s
-
pointer to a character sequence to return length of
[edit] Return value
The length of character sequence pointed to by s.
[edit] Complexity
Linear.
[edit] Example
Run this code
#include <iomanip> #include <iostream> #include <string> void print(const char* str) { std::cout << std::quoted (str) << " has length = " << std::char_traits <char>::length(str) << '\n'; } int main() { print("foo"); std::string s{"booo"}; print(s.c_str()); }
Output:
"foo" has length = 3 "booo" has length = 4