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std::basic_...ng::contains(3) C++ Standard Libarystd::basic_...ng::contains(3) NAME std::basic_string::contains - std::basic_string::contains Synopsis constexpr bool contains( std::basic_string_view<CharT,Traits> sv ) const (1) (since C++23) noexcept; constexpr bool (2) (since C++23) contains( CharT ch ) const noexcept; constexpr bool (3) (since C++23) contains( const CharT* s ) const; Checks if the string contains the given substring. The substring may be one of the following: 1) A string view sv (which may be a result of implicit conversion from another std::basic_string). 2) A single character ch. 3) A null-terminated character string s. All three overloads are equivalent to return find(x) != npos;, where x is the parameter. Parameters sv - a string view which may be a result of implicit conversion from another std::basic_string ch - a single character s - a null-terminated character string Return value true if the string contains the provided substring, false otherwise. Notes Feature-test macro Value Std Feature __cpp_lib_string_contains 202011L (C++23) contains functions Example // Run this code #include <iomanip> #include <iostream> #include <string> #include <string_view> #include <type_traits> template<typename SubstrType> void test_substring(const std::string& str, SubstrType subs) { constexpr char delim = std::is_scalar_v<SubstrType> ? '\'' : '\"'; std::cout << std::quoted(str) << (str.contains(subs) ? " contains " : " does not contain ") << std::quoted(std::string{subs}, delim) << '\n'; } int main() { using namespace std::literals; auto helloWorld = "hello world"s; test_substring(helloWorld, "hello"sv); test_substring(helloWorld, "goodbye"sv); test_substring(helloWorld, 'w'); test_substring(helloWorld, 'x'); } Output: "hello world" contains "hello" "hello world" does not contain "goodbye" "hello world" contains 'w' "hello world" does not contain 'x' See also starts_with checks if the string starts with the given prefix (C++20) (public member function) ends_with checks if the string ends with the given suffix (C++20) (public member function) find finds the first occurrence of the given substring (public member function) substr returns a substring (public member function) contains checks if the string view contains the given substring or character (C++23) (public member function of std::ba- sic_string_view<CharT,Traits>) http://cppreference.com 2024.06.10 std::basic_...ng::contains(3)
NAME | Synopsis | Parameters | Return value | Notes | Example | Output: | See also
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