Simple array/pointer question.

smoothdogg00 · 03-14-2006, 09:19 PM

If I declare a character array and want to add an item to the array, without having it point to that item, for example:

Code:

Code:

char * arr[50];
char temp[255];

for(loop where temp is always changing)
{
  array[i] = temp;
}
for(loop through array)
  printf("%s", array[i]);

Results:

Code:

same
same
same
same

How can I make it so that all elements in the array do not point to the current temp value, but point to what temp was at that time? I know its a pointer problem, but I don't really understand pointers that well.

spooon · 03-14-2006, 09:57 PM

this is C i presume?

First of all, do you understand how strings work in C?

temp is a pointer to the start of an array of 255 chars. I don't know what you're doing in the loop (you don't show us), but I'm guessing temp itself never changes; it's the contents of the array that you change. So if you want to keep the contents of that array for later, you're going to have to copy it somewhere. The "array[i] = temp" line makes each array[i] point to the same place that temp points to, but it does not copy the contents of the array.

xhi · 03-15-2006, 08:14 AM

for each ptr you will use in arr you will need to allocate memory and then copy the contents of temp to that new memory.

dont forget to free your memory when you are done.

jlliagre · 03-15-2006, 10:15 AM

Code:

...
array|i]=strdup(temp);
...