Replace non-alphanumeric characters in folder of files

Replace-irregular-chars.ps1

# Potential input
# -------------------------------------                                                                                                                                                                                                      
#  Test File With Spaces.txt                                                                                                                                                                                       
#  Test_File_With_Underscores.txt                                                                                                                                                                                  
#  Weird_Chars##$%@1.txt         

$badFiles = Get-ChildItem "C:\temp\irregular files"

foreach ($file in $badFiles)
{
    # Check for file extension
    $fileExt = (Split-Path -Path $file.Name -Leaf).Split(".")[1] 

    # Regex match any non-alphanumeric characters
    $fileNewName = ($file.BaseName -replace "[^a-zA-Z0-9 :]") + $fileExt

    Try { Rename-Item $file.FullName -NewName $fileNewName }
    Catch { $_ }
}

# Output
# -------------------------------------                                                                                                                                                                                                      
#  Test File With Spaces.txt                                                                                                                                                                                       
#  TestFileWithUnderscores.txt                                                                                                                                                                                  
#  WeirdChars1.txt