searching for a specific string cpp code example

Example 1: find character in string c++

auto char_to_find = 'a'
if (str.find(char_to_find) != std::string::npos) {
    // character found
}

Example 2: string .find in c++

std::string t = "Banana Republic";
std::string s = "nana";

std::string::size_type i = t.find(s);

if (i != std::string::npos)
   t.erase(i, s.length());