std::basic_string_view<CharT,Traits>::contains
constexpr bool contains( basic_string_view sv ) const noexcept; |
(1) | (since C++23) |
constexpr bool contains( CharT c ) const noexcept; |
(2) | (since C++23) |
constexpr bool contains( const CharT* s ) const; |
(3) | (since C++23) |
Checks if the string view contains the given substring, where.
1) the substring is a string view.
2) the substring is a single character.
3) the substring is a null-terminated character string.
All three overloads are equivalent to return find(x) != npos;, where x is the parameter.
Parameters
| sv | - | a string view |
| c | - | a single character |
| s | - | a null-terminated character string |
Return value
true if the string view contains the provided substring, false otherwise.
Notes
Feature testing macro: __cpp_lib_string_contains.
Example
#include <iostream>
#include <string_view>
auto main() -> int
{
using namespace std::literals;
std::cout
<< std::boolalpha
// bool contains(basic_string_view x) const noexcept;
<< "https://cppreference.com"sv.contains("cpp"sv) << ' ' // true
<< "https://cppreference.com"sv.contains("java"sv) << ' ' // false
// bool contains(CharT x) const noexcept;
<< "C++23"sv.contains('+') << ' ' // true
<< "C++23"sv.contains('-') << ' ' // false
// bool contains(const CharT* x) const;
<< std::string_view("basic_string_view").contains("string") << ' ' // true
<< std::string_view("basic_string_view").contains("String") << ' ' // false
<< '\n';
}
Output:
true false true false true false
See also
|
(C++20)
|
checks if the string view starts with the given prefix (public member function) |
|
(C++20)
|
checks if the string view ends with the given suffix (public member function) |
|
(C++17)
|
find characters in the view (public member function) |
|
(C++17)
|
returns a substring (public member function) |
|
(C++23)
|
checks if the string contains the given substring or character (public member function of std::basic_string<CharT,Traits,Allocator>) |
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https://en.cppreference.com/w/cpp/string/basic_string_view/contains
