// inkey-Working        by YBM
#include <conio.h>
#include <iostream>
#include <iomanip>
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <math.h>
using namespace std;
 
string spaz(int,string);
string datainp(string,int);
void msg() {cout << "\nPress Esc to Exit, Any other key to continue."; }
void presskey()
{
cout << "\n\nAny other key to continue.";
cin.ignore();
// cin.get();
// system("CLS");
}
 
void msg2()
{
cout << "\n// INPUT TYPE CONTROL";
cout << "\n// ------------------";
cout << "\n// Weight   Condition 3 Numbers and decimals only ";
cout << "\n\n";
}
 
char *endptr;
double weight;
std::string sweight;
int xc=0;
int condi;
std::string xcon;
char xconcate;
int getche(void);
int main(void)
{
  const char* xconcate;
  string efield="";
  // Weight Condition 3 Numbers and decimals only
  sweight="";
  efield="Weight";
  condi=3;
  sweight=datainp(efield,condi);
  cout << "\n  Validated Numbers and decimal, Weight: " << sweight << endl;
 return 0;
}
//   Data Entry subroutine
string datainp(string efield,int condi)
{
int xcond=condi;
int c;
int extended = 0;
 
redo:
std::string concate = "";
msg2();
msg();
condi==xcond;
cout << "\nCondition :" << condi << endl;
cout << "\n\n   Enter "<< efield << ": ";
  do
  {
    c = getche();
    if (c==27) { break; }
    char inp=c;       // assign char from ASCII code Backspace's ASCII code is 8
    if (!c)
      extended = getche();
      if (extended) {     }
      else if (condi==3) {      // Only Numbers and decimal allowed
        if ((c >=48 && c <=57) || (c>=46 && c<=46))
        {
          concate += inp; // string concatenation.. The character isn't extended
        }
        else { concate=spaz(c,concate);}
       }
  } while (c != 13);        // ascii 13 is <enter> or <carriage return>
  int len = concate.length();
  cout << "\n  String length =" << len << " chars" << endl;
  if (condi==3)       // Coversion from string to numeric.
  {
  cout << "\n  Weight entered as string = " << concate;
//  convert string to numeric variable
//   weight = strtod(concate,&endptr);
   cout <<"\n\n  strtod(concate,&endptr) Conversion from string to number is not working.. \n  Test weight is numeric, weight*10 = " << weight*10 << " " << endl;
  }
  return concate;
}  // main terminate
 
//   SUBROUTINE TO MOVE CURSOR POSITION
string spaz(int xc,string xconcate)
{
  if (xc !=8)    // not backspace
  {
    cout << "\x08";
  }
  else
  {
    int len = xconcate.length();
    if (len >0)
    {
      cout << " ";
      cout << "\x08";
      xconcate=xconcate.substr(0,len-1);
    }
    else
    {
      cout << " ";
    }
  }
return xconcate;
}

// cstr2.cpp
// Must compile using CODE::BLOCK
// Borland 5.02 does not work
#include <iostream>
#include <string>
#include <stdlib.h>
using namespace std;
void presskey()
{
cout << "\n\nAny other key to continue.";
cin.ignore();
cin.get();
system("CLS");
}
char *endptr;
double weight=0;
int main()
{
string concate;         // declare a string variable
int len; //  find out the number of characters in the string
cout << "Enter Weight: ";
getline(cin, concate);  // input string
len=concate.length();  //find the number of characters in the string
 
char xxc[len];  // initialize array
concate.copy( xxc, len ); //fills array in order with characters from the string
 
weight=strtod(xxc,&endptr);
cout << "Weight = " << weight;
 
presskey();
 
return 0;
}
 
*****************
END
 
 
START
**************************************
This is how i have incorporated the strtod() inside my program, where they were remarked out earlier:
 
    int len = concate.length();
    cout << "\n  String length =" << len << " chars" << endl;
    if (condi==3) {
    //  convert string to numeric variable
    char xxc[len];    // intialise array
    concate.copy(xxc,len); // fills in array with characters from the string
    weight = strtod(xxc,&endptr);    // weight declared as global double

  char *  myChar = "some text"

#include <string>
int main()
{
 
std::string str;
char * c = "No cover!";
 
str = c; //you can assing a c-string to a string
str[3]='h';//you can access the string as if it were an array
 
char const * c2 = str.c_str(); //it has to be const 
 
std::cout << c << std::endl ; 
std::cout << str << std::endl ;
std::cout << c2 << std::endl ;
 
//note that you cant do the following, it compiles but crashes, the reason is that C++ doesnt store the c-style string as an array
 
c[3] = 'h';
 
system("pause");
 
}