How to create number of lists at runtime in C#

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I need to create separate list for each elements in counts.

i.e if count==4 then the following list should be created

List<polygon> List1=new List<polygon>();
List<polygon> List2=new List<polygon>();
List<polygon> List3=new List<polygon>();
List<polygon> List4=new List<polygon>();

I need to concatenate the list names so that I can differentiate each list

How to create these list based on count at runtime

Posted 19-Mar-14 22:53pm

KUMAR619

Updated 19-Mar-14 23:04pm

v2

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4 solutions

Solution 1

I don't understand your scenario completely but perhaps an array of lists might help.

Posted 19-Mar-14 22:58pm

Abhinav S

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KUMAR619 20-Mar-14 5:01am

I have to declare a list at runtime concatenating the count number with list name to differentiate each list

Is it possible to create such lists at runtime

Solution 2

Just declare array at the first time.
Then at run time add one by one list of numbers to array
But You have to collect list of numbers in run time and your list should generate according to them

Posted 19-Mar-14 23:12pm

sankarsan parida

Solution 3

I didn't get your scenario as well, but I think you're looking for this,

int count = 5;
List<List<string>> lists = new List<List<string>>();

for (int i = 0; i < count; i++)
{
    lists.Add(new List<string>());
}

MessageBox.Show("" + lists.Count);

-KR

Posted 19-Mar-14 23:47pm

Krunal Rohit

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BillWoodruff · Accepted Answer · 2014-03-20T01:49:00

If it's essential to name these dynamically created Lists, you could use a Dictionary<string,List<int>>:

C#

Dictionary<string, List<int>> ListDict = new Dictionary<string, List<int>>();

int listsToBuild = 10;

// build the Lists
for (int i = 1; i <= listsToBuild; i++)
{
    ListDict.Add("List" + i.ToString(), new List<int>());
}

// store a value in one of the Lists
ListDict["List1"].Add(100);

// access a value in one of the Lists
int aValue = ListDict["List1"][0];

To create a new named variable at run-time would require reflection, and I doubt you want to get into that.