check if character is present in string c++ code example

Example 1: how to check string contains char in c++

std::string s = "Hello";
if (s.find('e') != std::string::npos)
    cout << "Found";
else
    cout << "Not Found";

Example 2: check if character in string c++

std::string s = "hell[o";
if (s.find('[') != std::string::npos)
    ; // found
else
    ; //

Example 3: c++ find string in string

#include <iostream>
#include <string>
#include <algorithm>
#include <functional>

int main()
{
    std::string in = "Lorem ipsum dolor sit amet, consectetur adipiscing elit,"
                     " sed do eiusmod tempor incididunt ut labore et dolore magna aliqua";
    std::string needle = "pisci";
    auto it = std::search(in.begin(), in.end(),
                   std::boyer_moore_searcher(
                       needle.begin(), needle.end()));
    if(it != in.end())
        std::cout << "The string " << needle << " found at offset "
                  << it - in.begin() << '\n';
    else
        std::cout << "The string " << needle << " not found\n";
}

Example 4: find in string c++

size_t find (const string& str, size_t pos = 0) const;