Passing 2D character array to function

[pebbert9]

Hello,

I am trying to pass 2D character arrays to a function, then step through the values. But, it's not working right.

Am I on the right track? Any help is appreciated.

[RF_Developer]

*ptr = list; // Changes what the pointer points to.

ptr = list; // This is what I think you need. Change the pointer itself.

[Ttelmah]

It is also worth realising that you don't have to have a second copy of the pointer inside the function.

Inside array_print, 'list', is a _local copy_ of the value passed to the function. So there is no need to copy this to 'ptr'. Just use it.

However there is a problem in terms of what you point to.

Start with speed. An array of three seven element string objects. So using '0' to indicate a null, and 'x' to indicate undefined, in memory:

Slow0xxMedium0Fast0xx

Now, 'speed' points to the first element in this, and inside array_print, so does 'list'. You call printf, and "Slow" gets printed, then increment ptr, or list (whichever you use), and it now points to the 'l', moving forward by one character.
Problem is that the pointer does not know about the size of the elements in the array, just knowing it points to 'characters', so when you increment it, it moves to the next _character_, not the next 'string'.....

In C, there are two ways of doing what you want. The first is if the arrays all have the same size rows, and your function can then be told this with a declaration like

char list[][7]

So the function knows the pointer is to an array, and to move forward by seven elements for the next row, or to pass the size of the row to the function, as:

[pebbert9]

thank you