find character in string c 2b 2b

1auto char_to_find = 'a'
2if (str.find(char_to_find) != std::string::npos) {
3    // character found
4}

1// string::find
2#include <iostream>       // std::cout
3#include <string>         // std::string
4
5int main ()
6{
7  std::string str ("There are two needles in this haystack with needles.");
8  std::string str2 ("needle");
9
10  // different member versions of find in the same order as above:
11  std::size_t found = str.find(str2);
12  if (found!=std::string::npos)
13    std::cout << "first 'needle' found at: " << found << '\n';
14
15  found=str.find("needles are small",found+1,6);
16  if (found!=std::string::npos)
17    std::cout << "second 'needle' found at: " << found << '\n';
18
19  found=str.find("haystack");
20  if (found!=std::string::npos)
21    std::cout << "'haystack' also found at: " << found << '\n';
22
23  found=str.find('.');
24  if (found!=std::string::npos)
25    std::cout << "Period found at: " << found << '\n';
26
27  // let's replace the first needle:
28  str.replace(str.find(str2),str2.length(),"preposition");
29  std::cout << str << '\n';
30
31  return 0;
32}