I'm new to powershell and trying to get the length of a HashTable (to use in a for loop), but I can't seem to get the length of the HashTable to output anything.
$user = #{}
$user[0] = #{}
$user[0]["name"] = "bswinnerton"
$user[0]["car"] = "honda"
$user[1] = #{}
$user[1]["name"] = "jschmoe"
$user[1]["car"] = "mazda"
write-output $user.length #nothing outputs here
for ($i = 0; $i -lt $user.length; $i++)
{
#write-output $user[0]["name"]
}
#{} declares an HashTable whereas #() declares an Array
You can use
$user.count
to find the length of you HashTable.
If you do:
$user | get-member
you can see all the methods and properties of an object.
$user.gettype()
return the type of the object you have.
$user is a hash table, so you should user$user.count instead.
That's not an array but a hashtable. Use .count instead:
write-output $user.count
Related
I have small error when running my code. I assign a string to custom object but it's parsing the string by itself and throwing an error.
Code:
foreach ($item in $hrdblistofobjects) {
[string]$content = Get-Content -Path $item
[string]$content = $content.Replace("[", "").Replace("]", "")
#here is line 43 which is shown as error as well
foreach ($object in $listofitemsdb) {
$result = $content -match $object
$OurObject = [PSCustomObject]#{
ObjectName = $null
TestObjectName = $null
Result = $null
}
$OurObject.ObjectName = $item
$OurObject.TestObjectName = $object #here is line 52 which is other part of error
$OurObject.Result = $result
$Resultsdb += $OurObject
}
}
This code loads an item and checks if an object exists within an item. Basically if string part exists within a string part and then saves result to a variable. I am using this code for other objects and items but they don't have that \p part which I am assuming is the issue. I can't put $object into single quotes for obvious reasons (this was suggested on internet but in my case it's not possible). So is there any other option how to unescape \p? I tried $object.Replace("\PMS","\\PMS") but that did not work either (this was suggested somewhere too).
EDIT:
$Resultsdb = #(foreach ($item in $hrdblistofobjects) {
[string]$content = Get-Content -Path $item
[string]$content = $content.Replace("[", "").Replace("]", "")
foreach ($object in $listofitemsdb) {
[PSCustomObject]#{
ObjectName = $item
TestObjectName = $object
Result = $content -match $object
}
}
}
)
$Resultsdb is not defined as an array, hence you get that error when you try to add one object to another object when that doesn't implement the addition operator.
You shouldn't be appending to an array in a loop anyway. That will perform poorly, because with each iteration it creates a new array with the size increased by one, copies all elements from the existing array, puts the new item in the new free slot, and then replaces the original array with the new one.
A better approach is to just output your objects in the loop and collect the loop output in a variable:
$Resultsdb = foreach ($item in $hrdblistofobjects) {
...
foreach ($object in $listofitemsdb) {
[PSCustomObject]#{
ObjectName = $item
TestObjectName = $object
Result = $content -match $object
}
}
}
Run the loop in an array subexpression if you need to ensure that the result is an array, otherwise it will be empty or a single object when the loop returns less than two results.
$Resultsdb = #(foreach ($item in $hrdblistofobjects) {
...
})
Note that you need to suppress other output on the default output stream in the loop, so that it doesn't pollute your result.
I changed the match part to this and it's working fine $result = $content -match $object.Replace("\PMS","\\PMS").
Sorry for errors in posting. I will amend that.
I'm trying add to a variable and a string in an array dynamically but i'm not getting expected output.
(1) I'm getting env name
(2) Concatinating the string and variable in an array
Code is as follows.
$env = $env:COMPUTERNAME.Substring(0,2)
$servers = { $env+"server1.test.com",$env+"server2.test.com" }
$serverCount = $servers -split(",") | measure | % { $_.Count }
For ($i=0; $i -lt $serverCount; $i++)
{
$ServerName = $servers -split(',') -replace '\[\d+\]'
$server = $ServerName[$i]
Write-Host $server
}
output i'm getting as
$env+"server1.test.com"
$env+"server2.test.com"
Values are not getting concatenated properly and variable value is not getting displayed. Any help.
$servers = { $env+"server1.test.com",$env+"server2.test.com" }
This is a scriptblock, not an array. {} is like a function, you have to run it for it to do anything (such as evaluating $env).
When you force it into a string using -split(",") what you get is text representation of the source code in the scriptblock, including the variable names.
As #Olaf comments, the right way to create an array of names is
$servers = ($env + "server1.test.com"), ($env + "server2.test.com")
This might be how I'd write it:
$env = $env:COMPUTERNAME.Substring(0,2)
"server1.test.com", "server2.test.com" | foreach-object {
"$env$_" -replace '\d+'
}
Why does this code not work?
$method = {
[System.Collections.ArrayList]$array;
for ($i=0; $i -le 50; $i++) { $array += $i }
}
Executing the scriptblock with:
&$method
Shows on the console:
1, 2, 3, 4, 5, 6
when it should print 50 numbers?
The Add() method of the ArrayList type emits the index at which a new item was inserted. Cast the expression to [void], pipe it to Out-Null or assign it to $null to supress this output:
[void]$array.Add($i)
# or
$array.Add($i) |Out-Null
# or
$null = $array.Add($i)
Avoid piping to Out-Null if you do this many times, casting or assigning is much faster than piping.
The code you posted shouldn't generate any output at all, unless you already have a variable $array defined in the parent scope. The statement
[System.Collections.ArrayList]$array
casts the value of the variable $array to the type ArrayList and echoes it. If the variable has a value in the parent scope the statement will output the value as an array list, otherwise the output will be null. The subsequent loop will not use that variable, but instead increment a new (local) variable $array. You can verify that by placing a statement $array.GetType().FullName at the end of the scriptblock. You'll get System.Int32, not System.Collections.ArrayList (or System.Object[]) as you might expect.
If you want to instantiate an ArrayList object, add numbers to it, and output that list at the end of the scriptblock, you need to change your code to something like this:
$method = {
[Collections.ArrayList]$array = #()
for ($i=0; $i -le 50; $i++) { $array += $i }
$array
}
Note the assignment operation in the first statement.
Demonstration:
PS C:\> $sb = { [Collections.ArrayList]$a; 0..50 | % { $a += $_ }; $a.GetType().FullName; $a }
PS C:\> &$sb
System.Int32
1275
PS C:\> $sb = { [Collections.ArrayList]$a = #(); 0..50 | % { $a += $_ }; $a.GetType().FullName; $a }
PS C:\> &$sb
System.Collections.ArrayList
0
1
...
49
50
This question already has answers here:
Powershell create array of arrays
(3 answers)
Closed 5 years ago.
This is building $ret into a long 1 dimensional array rather than an array of arrays. I need it to be an array that is populated with $subret objects. Thanks.
$ret = #()
foreach ($item in $items){
$subret = #()
$subRet = $item.Name , $item.Value
$ret += $subret
}
there might be other ways but arraylist normally works for me, in this case I would do:
$ret = New-Object System.Collections.ArrayList
and then
$ret.add($subret)
The suspected preexisting duplicate question is indeed a duplicate:
Given that + with an array as the LHS concatenates arrays, you must nest the RHS with the unary form of , (the array-construction operator) if it is an array that should be added as a single element:
# Sample input
$items = [pscustomobject] #{ Name = 'n1'; Value = 'v1'},
[pscustomobject] #{ Name = 'n2'; Value = 'v2'}
$ret = #() # create an empty *array*
foreach ($item in $items) {
$subret = $item.Name, $item.Value # use of "," implicitly creates an array
$ret += , $subret # unary "," creates a 1-item array
}
# Show result
$ret.Count; '---'; $ret[0]; '---'; $ret[1]
This yields:
2
---
n1
v1
---
n2
v2
The reason the use of [System.Collections.ArrayList] with its .Add() method worked too - a method that is generally preferable when building large arrays - is that .Add() only accepts a single object as the item to add, irrespective of whether that object is a scalar or an array:
# Sample input
$items = [pscustomobject] #{ Name = 'n1'; Value = 'v1'},
[pscustomobject] #{ Name = 'n2'; Value = 'v2'}
$ret = New-Object System.Collections.ArrayList # create an *array list*
foreach ($item in $items) {
$subret = $item.Name, $item.Value
# .Add() appends whatever object you pass it - even an array - as a *single* element.
# Note the need for $null = to suppress output of .Add()'s return value.
$null = $ret.Add($subret)
}
# Produce sample output
$ret.Count; '---'; $ret[0]; '---'; $ret[1]
The output is the same as above.
Edit
It is more convoluted to create an array of tuples than fill an array with PsObjects containing Name Value as the two properties.
Select the properties you want from $item then add them to the array
$item = $item | select Name, Value
$arr = #()
$arr += $item
You can reference the values in this array by doing this
foreach($obj in $arr)
{
$name = $obj.Name
$value = $obj.Value
# Do actions with the values
}
What I'm trying to do is create array variable names dynamically, and then with a loop, add the object to its relevant array based on the hash table value being equal to the counter variable.
$hshSite = #{} # Values like this CO,1 NE,2 IA,3
$counter = $hshSite.count
For($i = $counter; $i -gt 0; $i--) {
New-Variable -Name "arr$i" -Value #()
}
If $counter = 3, I would create arrays $arr1, $arr2, $arr3
$csv = Import-CSV....
ForEach ($x in $csv) {
#if $hshSite.Name = $x.location (ie CO), look up hash value (1),
and add the object to $arr1. If $hshSite.Name = NE, add to $arr2
I tried creating the dynamic arrays with New-Variable, but having issues trying to add to those arrays. Is it possible to concatenate 2 variables names into a single variable name? So taking $arr + $i to form $arr1 and $arr2 and $arr3, and then I can essentially just do $arr0 += $_
The end goal is to group things based on CO, NE, IA for further sorting/grouping/processing. And I'm open to other ideas of getting this accomplished. Thanks for your help!
Just make your hash table values the arrays, and accumulate the values to them directly:
$Sites = 'CO','NE','IA'
$hshSite = #{}
Foreach ($Site in $Sites){$hshSite[$Site] = #()}
ForEach ($x in $csv)
{
$hshSite[$x.location] += <whatever it is your adding>
}
If there's a lot of entries in the csv, you might consider creating those values as arraylists instead of arrays.
$Sites = 'CO','NE','IA'
$hshSite = #{}
Foreach ($Site in $Sites){ $hshSite[$Site] = New-Object Collections.Arraylist }
ForEach ($x in $csv)
{
$hshSite[$x.location].add('<whatever it is your adding>') > $nul
}
You could quite easily do add items to a dynamically named array variable using the Get-Variable cmdlet. Similar to the following:
$MyArrayVariable123 = #()
$VariableNamePrefix = "MyArrayVariable"
$VariableNameNumber = "123"
$DynamicallyRetrievedVariable = Get-Variable -Name ($VariableNamePrefix + $VariableNameNumber)
$DynamicallyRetrievedVariable.Value += "added item"
After running the above code the $MyArrayVariable123 variable would be an array holding the single string added item.