string substr c++

// string::substr
#include <iostream>
#include <string>

int main ()
{
  std::string str="We think in generalities, but we live in details.";
                                           // (quoting Alfred N. Whitehead)

  std::string str2 = str.substr (3,5);     // "think"

  std::size_t pos = str.find("live");      // position of "live" in str

  std::string str3 = str.substr (pos);     // get from "live" to the end

  std::cout << str2 << ' ' << str3 << '\n';

  return 0;
}String is: eek
// CPP program to illustrate substr() 
#include <string.h> 
#include <iostream> 
using namespace std; 
  
int main() 
{ 
    // Take any string 
    string s = "dog:cat"; 
  
    // Find position of ':' using find() 
    int pos = s.find(":"); 
  
    // Copy substring after pos 
    string sub = s.substr(pos + 1); 
  
    // prints the result 
    cout << "String is: " << sub; 
  
    return 0; 
} 
s.substr(pos,len);