Save value in array during iteration

Question

i have a function named GetFileList.Here am giving different extension to the function by seperating it using ;.My issue is that the value in the string[] FileList during the first iteration is losing during the second iteration.How can populate FileList with data from all iteation

public static string[] GetFileList(string Directory,string extensions)
   {
       string[] extensionlist = extensions.Split(';');
       FileList = new string[] { };
       foreach (string extension in extensionlist)
       {
           FileList =System.IO.Directory.GetFiles(Directory, "*." + extension, System.IO.SearchOption.AllDirectories);


       }
       return FileList;
   }

Amir Popovich · Accepted Answer · 2014-08-21 11:50:09Z

1

simply use AddRange and use a list for doing that:

public static string[] GetFileList(string Directory,string extensions)
   {
       string[] extensionlist = extensions.Split(';');
       List<string> FileList = new List<string>();
       foreach (string extension in extensionlist)
       {
           FileList.AddRange(System.IO.Directory.GetFiles(Directory, "*." + extension, System.IO.SearchOption.AllDirectories)); 
       }
       return FileList.ToArray();
   }

edited Aug 21, 2014 at 11:50

answered Aug 21, 2014 at 11:44

Amir Popovich

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2 Comments

mystack Over a year ago

am not using ArrayList.it is a sting[]

Aik Over a year ago

You have to use a collection. Array size is immutable than it can't grow. The issue is that you replace array reference with shiny new array and it is not an addition. You will finish with array from last iteration (contains only files with last extension)

Tim Schmelter · Accepted Answer · 2014-08-21 11:46:25Z

0

You can use LINQ:

string[] FileList =  extensions.Split(';').Distinct()
    .SelectMany(ex => System.IO.Directory.GetFiles(Directory, "*." + ex, SearchOption.AllDirectories))
    .ToArray();

answered Aug 21, 2014 at 11:46

Tim Schmelter

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Comments

Chamika Sandamal · Accepted Answer · 2014-08-21 12:04:40Z

0

Try following code if you are using .net 4.5+ Directory.EnumerateFiles will give more faster result

public static string[] GetFileList(string Directory, string extensions)
{
    string[] extensionlist = extensions.Split(';');
    var FileList = Directory.EnumerateFiles(Directory)
        .Where(file => extensionlist.Contains(Path.GetExtension(file))).ToArray<string>();
    return FileList;
}

edited Aug 21, 2014 at 12:04

answered Aug 21, 2014 at 11:54

Chamika Sandamal

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