`Sort` files, size

Files have varying sizes. In VB.NET, we can use Directory.GetFiles and OrderByDescending along with the FileInfo type to sort them from largest to smallest.

With this function, we can determine the largest file in a directory. This may be the most important file. Alternatively, we can find the smallest file.

Example

We first invoke Directory.GetFiles, which returns a string array of the files in the directory. Next, we invoke the OrderByDescending method.

Detail The OrderByDescending call is more complex. It receives a Func argument—this is an anonymous method.

Detail The Func method is created with anonymous method syntax. The Function receives a string (the file name) and returns its length.

So The OrderByDescending method sorts the files by their lengths. We then convert its result (an IEnumerable) into an array with ToArray.

Imports System.IO

Module Module1
    Sub Main()
        ' The target directory.
        Dim dir As String = "C:\\programs"

        ' Get files.
        Dim files() As String = Directory.GetFiles(dir)

        ' Order files from largest size to smallest size.
        Dim sorted() As String = files.OrderByDescending(
            New Func(Of String, Integer)(Function(fn As String)
                                             Return New FileInfo(fn).Length
                                         End Function)).ToArray

        ' Loop and display files.
        For Each element As String In sorted
            Console.WriteLine(element)
            Console.WriteLine(New FileInfo(element).Length)
        Next
    End Sub
End ModuleC:\\programs\file.py
611
C:\\programs\file.rb
369
C:\\programs\file.php
235
C:\\programs\file.pl
184

In the output, we see that the folder contains four script files. The largest is file.py—it is 611 bytes. The smallest meanwhile is file.pl which is 184 bytes.

Tip This program is inefficient. If you built a data structure (a List of KeyValuePairs) you could avoid accessing FileInfo so many times.

This program uses System.IO functions to get a file array and their sizes. And with OrderByDescending we specify a lambda expression (an anonymous method) to sort the file names.

Sort files, size

Example

`Sort` files, size