Arrays' initial value - how do you set it?!

Simon

Assume an array:

double[,] array = new double[x,y];

I know that the elements will be initialised to zero but I want to set every one of the array to a 'double.NaN'.

I did initially try a foreach loop, but the compiler complained. The only other way is two nested 'for' loops acting with x and y. Is there an easier way?

7 Replies

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Simon17y ago
Nope, doesn't work for me...

I cannot find anything on the 'net or in msdn/help/microsoft/books that allows you to set a multi dimensioned array to one value in one line of code...I'll just have to write two 'for' loops :(
Simon17y ago
Stefan - that is so simple why didn't I think of that...!

Thank you for your time and efforts - very appreciated :)
Stefan17y ago
Hello,

I figured out how to do this in a foreach loop. Here's how:

int[,] array = new int[2, 3];
foreach (int index in array)
{
array[index, index] = 10;
}

When I tested this, I added each array object to a list box. When I ran the app, the list box displayed the each object in the array, all set to 10.

Hope this helps!
Simon17y ago
This compiles and runs properly...

#include "stdafx.h"

#include

int _tmain(int argc, _TCHAR* argv[])

{

float b[2][2] = {4.5};

for(int i = 0; i < 2; i++)

for(int j = 0; j < 2; j++)

std::cout << "\t" << b[i,j];

return 0;

}

I appreciate your help Stefan - thank you!
Stefan17y ago
You can't do this since you are using a multi-dimensional array. The example of a C++ array that you gave is a one-dimensional array.
Simon17y ago
No, not quite. What I was after is that in C++ you can do this:

float SomeArray[1000] = {9.5f};

And this sets all 1000 elements to the value of 9.5. What I would like to find out is if I can set a C# array in an equally easy manner - as the alternatives are either clumsy or not allowed by the compiler e.g.

double [,] SomeArray = new double[x,y];

for( int i = 0; i < x; i++)

   for( int j = 0; j < y; j++)

      SomeArray[i,j] = double.NaN;

This is just clumsy in comparison to C++, whereas the code below isn't allowed:

foreach (var a in double)

{

   a = double.NaN;

}

What am I missing...?!
Stefan17y ago
Are you asking how to initialize a multi-dimensional array?

If so, you would do something like this:

int [,] rectangularArray =
{
{0, 1, 2} {3, 4, 5}, {6, 7, 8}, {9, 10, 11}
};

This creates an array, implies the size of the rows and columns, and initializes the values. To read the values, however, you still need the nested for loops.

I hope this is what you were looking for. If not, please post back.