Issue with String Manipulation in Powershell TrimEnd()

Question

I have this PowerShell script that renames a file. The following is part of the string manipulation code (not my actual code, just to show the issue):

$text="String1.txt"
$text
$text.trimend(".txt")
$date=Get-Date -format yyyyMMdd
$text + $date
$newFile = $text.trimend(".txt") + "_" + $date + ".bak"
$newFile
$NewFile1 = $newFile.TrimEnd("_$date.bak") + ".bak"
$NewFile1

The result is:

String1.txt
String1
String1.txt20131104
String1_20131104.bak
String.bak

Why was the 1 at the end of String1 removed as well? I am expecting the result to be String1.bak .

Answer 1

The trimend() method takes a character array (not string) argument, and will trim all of the characters in the array that appear at the end of the string.

I usually use the -replace operator for trimming off a string value:

$text="String1.txt"
$text 
$text = $text -replace '\.txt$',''
$text

String1.txt
String1

Answer 2

Developing on the answer at PowerShell to remove text from a string , I'm using these regex's to trim off an extension of unkown type with possible . elsewhere in the filename:

$imagefile="hi.there.jpg"
$imagefile
hi.there.jpg
$imagefile -replace '\.([^.]*)$', ''
hi.there
$imagefile -replace '([^.]*)$', ''
hi.there.