Answers for "string c++ indexof"

index string c++

#include <string>
#include <iostream>

int main(){
  //index string by using brackets []
  std::string string = "Hello, World!";
  //assign variable to string index
  char stringindex = string[2];
  
}

c++ string contains

if (string1.find(string2) != std::string::npos) {
    std::cout << "found!" << 'n';
}

none

// string::operator[]
#include <iostream>
#include <string>

int main ()
{
  std::string str ("Test string");
  for (int i=0; i<str.length(); ++i)
  {
    std::cout << str[i];
  }
  return 0;
}

std string find character c++

// string::find
#include <iostream>       // std::cout
#include <string>         // std::string

int main ()
{
  std::string str ("There are two needles in this haystack with needles.");
  std::string str2 ("needle");

  // different member versions of find in the same order as above:
  std::size_t found = str.find(str2);
  if (found!=std::string::npos)
    std::cout << "first 'needle' found at: " << found << 'n';

  found=str.find("needles are small",found+1,6);
  if (found!=std::string::npos)
    std::cout << "second 'needle' found at: " << found << 'n';

  found=str.find("haystack");
  if (found!=std::string::npos)
    std::cout << "'haystack' also found at: " << found << 'n';

  found=str.find('.');
  if (found!=std::string::npos)
    std::cout << "Period found at: " << found << 'n';

  // let's replace the first needle:
  str.replace(str.find(str2),str2.length(),"preposition");
  std::cout << str << 'n';

  return 0;
}