C++ From Year 1995 File From "J"

 // Filename : JellyB1.CPP

// Demonstration of pointer scope issues

//

#include <iostream.h>

#include <string.h>

struct JellyBean

  {

    int i;

    int j;

    char* str;

  };

  

void main()

  {

    JellyBean red = {1,2,0};

    red.str = new char[30];

    

    strcpy(red.str,"A red jelly bean");

    

    JellyBean anotherRed = red;

    

    // But now both red.str and anotherRed

    // point to str

    

    cout << anotherRed.i << ", "

         << anotherRed.j << ", "

         << anotherRed.str;

    strcpy(red.str,"A blue jelly bean");

    

    // Is this a surprise? 

    cout << endl << "After assignment to red:" << endl;

    cout << anotherRed.i << ", "

         << anotherRed.j << ", "

         << anotherRed.str;

    

    delete [] red.str;

    red.str = 0; // Good practise

    // What does anotherRed.str equal? 

    //

    // Another small experiement

    //           

    {

      char newString[] =        "Oh! no! not the comfy chair!           ";

      red.str = newString;

    } // newString no longer exists

    {

      char anotherNewString[] = "No one expects the Spanish Inquisition!";

      cout << endl << red.str;  // red.str should point to newString???

    }

  }