need RELIABLE test for null/empty string, please!!

i've been testing with

get folder contents , put them arrays, save arrays

$content = $folder1 + $folder2

$content should empty string '' or have string value containing array data

we want send email if $content has value

if ($content) empty {

exit
else ($content has value)

send email

)

i can not reliably test value of $content

using ps 2.0 on win7 x64 if matters.

really need reliable test empty string resulting no files existing in both folder1 , folder2!!

thank you, tom

if there files returen $files1, $files1 test "true" on if,

so  if ($files1 -and $files2) execute if there in both $files1 , $files2.

if either 1 empty if ($files1 -and $files2) return $false, , it's script block not execute.

you can test how variable or expression react in if casting [bool]

 

ps c:\testfiles> $files1 = gci *.txt
ps c:\testfiles> $files1

    directory: c:\testfiles

mode                lastwritetime     length name
----                -------------     ------ ----
-a---          5/5/2010   9:24 pm         29 test 1.txt
-a---          5/5/2010   9:14 pm         29 test.txt
-a---         5/10/2010   7:29 pm        506 test2_evt.txt
-a---         4/26/2010   7:46 pm     486086 testa.txt
-a---         5/21/2010   7:31 am         15 testn.txt

ps c:\testfiles> [bool]$files1

true

ps c:\testfiles> $files2 = gci *.jpg
ps c:\testfiles> $files2

                                                    <----no jpg files, $files2 empty/null
ps c:\testfiles> [bool]$files2
false

ps c:\testfiles> [bool]($files1 -and $files2)
false

ps c:\testfiles> [bool]($files1 -or $files2)
true

ps c:\testfiles> $files3 = gci *.csv
ps c:\testfiles> $files3

    directory: c:\testfiles

mode                lastwritetime     length name
----                -------------     ------ ----
-a---         5/24/2010   8:12 pm        291 12_23_2009_evt.csv
-a---         5/24/2010   8:12 pm      46134 3_12_2010_evt.csv
-a---         5/24/2010   8:12 pm       4284 3_13_2010_evt.csv

ps c:\testfiles> [bool]($files1 -and $files3)
true
ps c:\testfiles>

---

[string](0..33|%{[char][int](46+("686552495351636652556262185355647068516270555358646562655775 0645570").substring(($_*2),2))})-replace " "

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