std::basic_string::rfind

size_type rfind( const basic_string& str, size_type pos = npos ) const;

size_type rfind( const CharT* s, size_type pos, size_type count ) const;

size_type rfind( const CharT* s, size_type pos = npos ) const;

size_type rfind( CharT ch, size_type pos = npos ) const;

Finds the last substring equal to the given character sequence. Search begins at pos, i.e. the found substring must not begin in a position following pos. If npos or any value not smaller than size() is passed as pos, whole string will be searched.

Parameters

Return value

Position of the first character of the found substring or npos if no such substring is found. Note that this is an offset from the start of the string, not the end.

If size() is zero, npos is always returned.

If searching for an empty string (str.size(), count, or strlen(s) is zero) returns pos (the empty string is found immediately) unless pos == npos, in which case returns size().

Exceptions

Example

#include <string>
#include <iostream>
 
void print(std::string::size_type n, std::string const &s)
{
    if (n == std::string::npos) {
        std::cout << "not found\n";
    } else {
        std::cout << "found: \"" << s.substr(n) << "\" at " << n << '\n';
    }
}
 
int main()
{
    std::string::size_type n;
    std::string const s = "This is a string";
 
    // search backwards from end of string
    n = s.rfind("is");
    print(n, s);
    // search backwards from position 4
    n = s.rfind("is", 4);
    print(n, s);
    // find a single character
    n = s.rfind('s');
    print(n, s);
    // find a single character
    n = s.rfind('q');
    print(n, s);
}

found: "is a string" at 5
found: "is is a string" at 2
found: "string" at 10
not found

See also