How to create an array of List<int> in C#?

Question

I have a problem where I need an array of arrayList.

For example if we take an Array of ArrayList of int, it will be like:

int[]<List> myData = new int[2]<List>;

myData[0] = new List<int>();
myData[0].Add(1);
myData[0].Add(2);
myData[0].Add(3);


myData[1] = new List<int>();
myData[1].Add(4);
myData[1].Add(5);
myData[1].Add(6);

myData[0].Add(7);

How can we implement a datastructure like the above in C#?

In C, its like a array of LinkedList. How can I do the same in C#?

Answer 1

var myData = new List<int>[]
{
    new List<int> { 1, 2, 3 },
    new List<int> { 4, 5, 6 }
};

Answer 2

Almost as you tried, only the first line is incorrect:

List<int>[] myData = new List<int>[2];
myData[0] = new List<int>();
myData[0].Add(1);
myData[0].Add(2);
myData[0].Add(3);


myData[1] = new List<int>();
myData[1].Add(4);
myData[1].Add(5);
myData[1].Add(6);

myData[0].Add(7);

Thanks to madmik3, here is a link you can read something about generic lists in C#: click me

Also, if you want to read something about arrays, eg the static copy method of the Array class, here is some link for that.

Answer 3

var arraySize = 2;
var myArray = new List<Int32>[arraySize];


myArray[0] = new List<Int32>();
myArray[1] = new List<Int32>();
// And so on....

myArray[0].Add(5);

Answer 4

I prefer lists but it's up to you...

List<List<int>> lst = new List<List<int>>();

lst.Add(new List<int>());
lst.Add(new List<int>());

lst[0].Add(1);
lst[1].Add(1);
lst[1].Add(2);
lst[0].Add(5);

Then if you really want a list at the end of it all use some linq.

lst.ToArray();

Answer 5

You're trying to take the concrete type List<int> and make an array of it.
Just like string becomes new string[2] , so to List<int> becomes new List<int>[2] .

This will create an array which can hold two List<int> s.
However, each element in the array starts out null .
You'll need to put a new List<int>() into each slot of the array before using it.

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However, you should probably use a List<List<int>> instead of an array of lists.