convert string to long double c++ code example

Example 1: how to convert a string to a double c++

double new = std::stod(string);

Example 2: c++ changing string to double

#include <iostream>
using namespace std;
int main() {
   char s[20] = "18.2894 is a number";
   char *p;
   double result;
   result = strtod(s, &p);
   cout<<"The number after conversion of string : "<<result;
   return(0);
}