🚀 go-pugleaf

"SKAS" <f93c0532@yahoo.com> wrote in message news:<acv9rh$sopon$1@ID-31123.news.dfncis.de>...
> I've written a class for string datatype.  The program runs fine but crashes
> in the end . However if I initialize the variable po in the main function
>  int i, po= 8;) instead of getting it from the user (cin >>po) the program
> exits nicely and doesn't crash.
> I'll be very grateful for any assistance. I'm using turbo c++ 3.0.
> 
> Thanks
> 
> 
> #include <iostream.h>
> #include <conio.h>
> #include <stdio.h>
> #include <string.h>
> 
> class string
> {
>  private:
>       char *head;
>       int len;
>  public:
>       string()
>    {
>    }
^^^^^^^ initialize head in the default constructor:
    string():head(0) {}
> 
>   string(int l)
>   {
>    len=l;
>    head=new char[len];
>   }
> 
>   string(char a[])
>   {
>    strcpy(head,a);
^^^^^^^^^ trouble - head is not initialized before strcpy
>   }
    string(const char* a)
    {
        l = strlen(a);
        head = new char[l + 1];
        
        strcpy(head, a);
    }


> 
>   ~string()
>   {
>      delete head;
>   }

// code snipped

> 
> void main(void)
> {
>  char sub[30],j;
>  int i,po;
>  string s1("the 1st and most IMPORTANT thing");
^^^^^^^^^^^^^^^^^ call to the trouble constructor

>  clrscr();
>  s1.print();
>  cout<<endl<<"The length of string (including null character)=
> "<<s1.length();
>  cout<<"\nEnter the index for a single character value: ";
>  cin>> po;  /* NOTE : IF INITIALIZE PO ABOVE INSTEAD OF GETTING IT FROM THE
> USER. PROGRAM WORKS FINE*/
>   cout<<"\nThe character at position "<<po<<" is \""<<s1.atindex(po)<<"\"";
>  s1.upper();
>  cout<<"\nThe string converted to upper case: ";
>  s1.print();
>  s1.lower();
>  cout<<"\nThe string converted to lower case: ";
>  s1.print();
>  s1.proper();
>  cout<<"\nThe string converted to proper case: ";
>  s1.print();
>  cout<<"\nEnter a substring to be searched in the main string: ";
>  gets(sub);
>  i=s1.substring(sub);
>  if (i != -1)
>   cout<<"The position of \""<<sub<<"\" is at index = "<<i;
>  else
>   cout<<"Substring not found!!!";
>  getch();
> }


po has nothing to do with it. it was just a side effect.

Dan