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Hi!

How to pass an (multidimensional)array of something to a function with
reference/pointer?

Can anyone help me with that?

Thanks,
Ohmu

"Ohmu" <> wrote in message
news: om...
> Hi!
>
> How to pass an (multidimensional)array of something to a function with
> reference/pointer?
>
> Can anyone help me with that?
>
> Thanks,
> Ohmu

Here's how to prototype and call functions with arrays, references and
pointers.

// one dimension with pointer
void function(int *a);
int array[10];
function(array);

// two dimensions with pointer
void function(int (*a)[20]);
int array[10][20];
function(array);

// three dimensions with pointer
void function(int (*a)[20][30]);
int array[10][20][30];
function(array);


// one dimension with reference
void function(int (&a)[10]);
int array[10];
function(array);

// two dimensions with reference
void function(int (&a)[10][20]);
int array[10][20];
function(array);

// three dimensions with reference
void function(int (&a)[10][20][30]);
int array[10][20][30];
function(array);

john

"John Harrison" <> wrote in message news:<biplo1$bqaq9$>...
> Here's how to prototype and call functions with arrays, references and
> pointers.
>
> // one dimension with pointer
> void function(int *a);
> int array[10];
> function(array);
>
<snip>
> // one dimension with reference
> void function(int (&a)[10]);
> int array[10];
> function(array);
<snip>
>
> john

but how to pass the array when the size is read from file, int array[size][size] ??

Ohmu

"Ohmu" <> wrote in message
news: om...
> "John Harrison" <> wrote in message
news:<biplo1$bqaq9$>...
> > Here's how to prototype and call functions with arrays, references and
> > pointers.
> >
> > // one dimension with pointer
> > void function(int *a);
> > int array[10];
> > function(array);
> >
> <snip>
> > // one dimension with reference
> > void function(int (&a)[10]);
> > int array[10];
> > function(array);
> <snip>
> >
> > john
>
> but how to pass the array when the size is read from file, int
array[size][size] ??
>
> Ohmu

int array[size][size]; is not a legal array declaration.

If your 2d array is dynamic then you need to allocate some memory for it and
use pointers. E.g.

void function(int** a);

int **array;
array = new int*[size];
for (int i = 0; i < size; ++i)
array[i] = new int[size];
function(array);

This question is in the FAQ

http://www.parashift.com/c++-faq-lit...html#faq-16.15

john