pointer to pointer problems

[stuartd]

Hi,

I am trying to get a sizeable multi dimension array using char **

ie
main()
{
char **data;

data[0]=new char[6];
strcpy(data[0],"Hello"
data[1]=new char[6];
strcpy(data[1],"World"

int x;
while(data[x] !=NULL)
{
printf("%s\n",data[x]); x++;
}
}

This causes a segmentation fault. What an i doing wrong?

 

[Kenrae]

You aren't allocating memory for pointer data. data[0] doesn't exist. You should do:

main()
{
   char **data;

   data=new *char[8] //This way you'll have 8 pointers.
   //You can also do data=malloc(8*sizeof(char*)).

   data[0]=new char[6];
   strcpy(data[0],"Hello");
   data[1]=new char[6];
   strcpy(data[1],"World");              

   int x=0;
   while(x<8 && data[x]!=NULL)
   {                
      printf(&quot;%s\n&quot;,data[x]); x++;          
   }
}

And you're supposing that compiler initializes those pointers (data[x]) to NULL. This can be false.

 

[stuartd]

Thanks - that is exactly what I want to do.