Two dimensional array initialization

Dadi <da**@hugur.i s> wrote:

I can make a simple initialization work like this:

Object[,] ONE_ROW = {{"Vodafone", "55501601001970 16"}};

But, now I want to create another array that consists of multiple copies
of ONE_ROW like this (will not compile):

It sounds like you want jagged arrays then, rather than rectangular
arrays. If you do:

Object[][,] TWO_ROWS = {ONE_ROW, ONE_ROW}; I believe it'll work.

(Haven't tried it though...)

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

Nov 15 '05 #2

Actually Jon I think he wants

Object[][] TWO_ROWS =

a jagged array of ONE_ROW arrays. Your code would be a jagged array of 2D
rectangular arrays which I don't think was the intent, wouldn't it?

I've been wrong about arrays before so maybe I am again.

"Jon Skeet [C# MVP]" <sk***@pobox.co m> wrote in message
news:MP******** *************** *@msnews.micros oft.com...

Dadi <da**@hugur.i s> wrote:
I can make a simple initialization work like this:

Object[,] ONE_ROW = {{"Vodafone", "55501601001970 16"}};

But, now I want to create another array that consists of multiple copies
of ONE_ROW like this (will not compile):

It sounds like you want jagged arrays then, rather than rectangular
arrays. If you do:

Object[][,] TWO_ROWS = {ONE_ROW, ONE_ROW}; I believe it'll work.

(Haven't tried it though...)

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

Nov 15 '05 #3

Daniel Billingsley <db**********@N O.durcon.SPAAMM .com> wrote:

Actually Jon I think he wants

Object[][] TWO_ROWS =

a jagged array of ONE_ROW arrays. Your code would be a jagged array of 2D
rectangular arrays which I don't think was the intent, wouldn't it?

I don't know - the intent wasn't very clear! However, my code would
give a single array of 2D rectangular arrays.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

Nov 15 '05 #4

That's what I said, isn't it? :)

I meant your overall array [][,] would be jagged, as opposed to simply 3D
[,,].

Yes, no, maybe so? (Trying to see if I'm starting to grasp this terminology
as well as I think I am.)

"Jon Skeet [C# MVP]" <sk***@pobox.co m> wrote in message
news:MP******** *************** *@msnews.micros oft.com...

... Your code would be a jagged array of 2D
rectangular arrays which I don't think was the intent, wouldn't it?

I don't know - the intent wasn't very clear! However, my code would
give a single array of 2D rectangular arrays.

Nov 15 '05 #5

Daniel Billingsley <db**********@N O.durcon.SPAAMM .com> wrote:

That's what I said, isn't it? :)
Not quite - it's definitely *not* a jagged array *of* 2D rectangular
arrays, in the same way that int[] isn't a jagged array of ints, it's
just an array of ints, if you see what I mean.
I meant your overall array [][,] would be jagged, as opposed to simply 3D
[,,].

I'm not sure whether I'd say the overall array is jagged or not - it's
certainly not rectangular, but it's not jagged in the normal sense
either.

Fortunately this is unlikely to actually be an issue very often :)

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

Nov 15 '05 #6

Hmm... I thought jagged simply meant an array of arrays... what did you mean
by the "normal sense" of jagged usage?

an array of ints is 1 dimensional, and not relevant to this discussion in my
mind.

an array of arrays, or an array of arrays of arrays, or an array of 2D
arrays, are all "jagged" I would think by definition, no?

[,] defines 2D array, definitely not jagged
[][] defines array of arrays, definitely jagged

[][,] defines an array of 2D arrays, jagged, right?
[][][] defines an array of arrays of arrays, jagged, right?
[,,] defines a 3D array, not jagged, right?

"Jon Skeet [C# MVP]" <sk***@pobox.co m> wrote in message
news:MP******** *************** *@msnews.micros oft.com...

Daniel Billingsley <db**********@N O.durcon.SPAAMM .com> wrote:
That's what I said, isn't it? :)

Not quite - it's definitely *not* a jagged array *of* 2D rectangular
arrays, in the same way that int[] isn't a jagged array of ints, it's
just an array of ints, if you see what I mean.
I meant your overall array [][,] would be jagged, as opposed to simply 3D [,,].

I'm not sure whether I'd say the overall array is jagged or not - it's
certainly not rectangular, but it's not jagged in the normal sense
either.

Fortunately this is unlikely to actually be an issue very often :)

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

Nov 15 '05 #7

Daniel Billingsley <db**********@N O.durcon.SPAAMM .com> wrote:

Hmm... I thought jagged simply meant an array of arrays... what did you mean
by the "normal sense" of jagged usage?
I'd say that a jagged array of "X"s is an array of arrays of "X"s.
an array of ints is 1 dimensional, and not relevant to this discussion in my
mind.
Ah, but it is in mine. Here's a jagged array of ints:

int[][] x;

That means a jagged array *of* arrays is similarly:

Something[][][] x;

That's a jagged array of (Something[]).

Just

Something[][] x;

is a jagged array of (Something) instead.

In this case we have:

Something[][,];

which is a one-dimensional array of (Something[,]), rather than a
jagged array of Something[,]. It may or may not (see below) count as a
jagged array of Something. Semi-jagged perhaps?
an array of arrays, or an array of arrays of arrays, or an array of 2D
arrays, are all "jagged" I would think by definition, no?

Not sure. Possibly, possibly not. My main point was that it wasn't a
jagged array of 2D arrays, but now we're getting into deeper water :)

I keep flip-flopping on whether or not I'd consider it jagged in
general. I think I probably would, on balance, contrary to my previous
post.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

Nov 15 '05 #8

I'm sure where you landed when you flip-flopped, so I don't know if we're
still disagreeing. :)

"Jon Skeet [C# MVP]" <sk***@pobox.co m> wrote in message
news:MP******** *************** *@msnews.micros oft.com...

Daniel Billingsley <db**********@N O.durcon.SPAAMM .com> wrote:
Hmm... I thought jagged simply meant an array of arrays... what did you mean by the "normal sense" of jagged usage?
I'd say that a jagged array of "X"s is an array of arrays of "X"s.

Yes I agree. MS defines a jagged array as "an array whose elements are
arrays." But there is no specification of what that second "of arrays"
looks like - 1D, 2D, 3D doesn't change the definition.

Something[][,];

which is a one-dimensional array of (Something[,]), rather than a
jagged array of Something[,]. It may or may not (see below) count as a
jagged array of Something. Semi-jagged perhaps?
Is Something[,] not an array? Then that makes Something[][,] an
array of arrays, and therefore jagged by definition, just as MS explains a
bit further down on that same doc page:

"It is possible to mix jagged and multidimensiona l arrays. The following is
a declaration and initialization of a single-dimensional jagged array that
contains two-dimensional array elements of different sizes:

int [] [,] myJaggedArray = new int [] [3,] { new int [,] " blah blah blah

Not sure. Possibly, possibly not. My main point was that it wasn't a
jagged array of 2D arrays, but now we're getting into deeper water :)

Sure looks to me like MS just said [][,] is a jagged array of 2D arrays.

I'm sorry, I'm not trying to be a smart alec proving you wrong per se.. it's
just that I find myself completely confused and wrong enough that when I
think I've got something nailed for once I've got to cling to it
desperately. LOL.

Nov 15 '05 #9

Multi-dimensional array allocation with single 'new' call

I meant I'm *NOT* sure, of course. I've been typing like a retard all day.
Need coffee.

"Daniel Billingsley" <db**********@N O.durcon.SPAAMM .com> wrote in message
news:us******** ******@TK2MSFTN GP11.phx.gbl...

I'm sure where you landed when you flip-flopped, so I don't know if we're
still disagreeing. :)

Nov 15 '05 #10

Similar topics

7660

by: ip4ram | last post by:

I used to work with C and have a set of libraries which allocate multi-dimensional arrays(2 and 3) with single malloc call. data_type **myarray = (data_type**)malloc(widht*height*sizeof(data_type)+ height* sizeof(data_type*)); //allocate individual addresses for row pointers. Now that I am moving to C++,am looking for something by which I can

Multi-dimensional array initialization

26527

by: Grumble | last post by:

Hello, Is it not legal in C90 to initialize a multi-dimensional array with a one-dimensional initializer as done below? int a = { 1, 2, 3, 4, 5, 6, 7, 8 }; My compiler complains: example.c:1: warning: missing braces around initializer example.c:1: warning: (near initialization for `a')

C multi-dimensional arrays and pointers

2245

by: Richard Hayden | last post by:

Hi, Why does gcc (3.3.2) give me a 'initialization from incompatible pointer type' warning when compiling: int main(int argc, char** argv) { int testa; int** testp = testa; }

program that return an address of multi dimensional array

5820

by: ashu | last post by:

look at code #include<stdio.h> int *mult(void); int main(void) { int *ptr,i; ptr=mult; for(i=0;i<6;i++) { printf("%d",*(ptr++));

Numeric N-dimensional array initialization

2303

by: TG | last post by:

Hi there ! I'm just starting to use Numeric here, and I'm wondering : how can I efficiently initialize every values of a N-dimensional array, given I don't know the number of dimensions ? I'm looking for something like a map function, or a way to conveniently iterate through the whole N-array, but I didn't find anything ... yet. If anyone has a clue, I'm listening.

Python

2668

Arbitrary length multi-dimensional arrays

by: kd | last post by:

Newbie question here. It's been a while since I've done C programming, and I hit a wall last night. Let's say I have a three dimensional array, like so: int p = {{{0,0,0}, {1,1,1}, {0,1,0}},

Multi-Dimensional Arrays In PHP ... ???

1624

by: David T. Ashley | last post by:

Hi, Aside from the obvious recursive syntax for initialization, $x = array( ... array( ...)), what is the best way to deal with multi-dimensional arrays in PHP? It seems there is no syntax like $x???

PHP

559

multi dimensional array

by: Gernot Frisch | last post by:

Hi, I need a class, that has a 4 dimensional array (can be 3 dimensional, too) with such an operator: T operator()(int x1, int x2=0, int x3=0, int x4=0); that can be used as:

multi dimensional arrays as one dimension array

152

9820

by: vippstar | last post by:

The subject might be misleading. Regardless, is this code valid: #include <stdio.h> void f(double *p, size_t size) { while(size--) printf("%f\n", *p++); } int main(void) { double array = { { 3.14 }, { 42.6 } }; f((double *)array, sizeof array / sizeof **array); return 0;

Problem With Comparison Operator <=> in G++

8889

by: Oralloy | last post by:

Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed. This is as boiled down as I can make it. Here is my compilation command: g++-12 -std=c++20 -Wnarrowing bit_field.cpp Here is the code in...