How to convert string to integer in PowerShell - powershell

Question

I have a list of directories with numbers. I have to find the highest number and and increment it by 1 and create a new directory with that increment value. I am able to sort the below array, but I am not able to increment the last element as it is a string.
How do I convert this below array element to an integer?
PS C:\Users\Suman\Desktop> $FileList
Name
----
11
2
1

Answer 1

You can specify the type of a variable before it to force its type. It's called (dynamic) casting (more information is here):
$string = "1654"
$integer = [int]$string
$string + 1
# Outputs 16541
$integer + 1
# Outputs 1655
As an example, the following snippet adds, to each object in $fileList, an IntVal property with the integer value of the Name property, then sorts $fileList on this new property (the default is ascending), takes the last (highest IntVal) object's IntVal value, increments it and finally creates a folder named after it:
# For testing purposes
#$fileList = #([PSCustomObject]#{ Name = "11" }, [PSCustomObject]#{ Name = "2" }, [PSCustomObject]#{ Name = "1" })
# OR
#$fileList = New-Object -TypeName System.Collections.ArrayList
#$fileList.AddRange(#([PSCustomObject]#{ Name = "11" }, [PSCustomObject]#{ Name = "2" }, [PSCustomObject]#{ Name = "1" })) | Out-Null
$highest = $fileList |
Select-Object *, #{ n = "IntVal"; e = { [int]($_.Name) } } |
Sort-Object IntVal |
Select-Object -Last 1
$newName = $highest.IntVal + 1
New-Item $newName -ItemType Directory
Sort-Object IntVal is not needed so you can remove it if you prefer.
[int]::MaxValue = 2147483647 so you need to use the [long] type beyond this value ([long]::MaxValue = 9223372036854775807).

Answer 2

Example:
2.032 MB (2,131,022 bytes)
$u=($mbox.TotalItemSize.value).tostring()
$u=$u.trimend(" bytes)") #yields 2.032 MB (2,131,022
$u=$u.Split("(") #yields `$u[1]` as 2,131,022
$uI=[int]$u[1]
The result is 2131022 in integer form.

Answer 3

Use:
$filelist = #(11, 1, 2)
$filelist | sort #{expression={$_[0]}} |
% {$newName = [string]([int]$($_[0]) + 1)}
New-Item $newName -ItemType Directory

Answer 4

Use:
$filelist = #("11", "1", "2")
$filelist | sort #{expression={[int]$_}} | % {$newName = [string]([int]$_ + 1)}
New-Item $newName -ItemType Directory

Answer 5

If someone is looking for how this can be run from command line, as a single command, this is one way it can be done:
$FileList | ` # Writes array to pipeline
Select-Object -Last 1 | ` # Selects last item in array
ConvertFrom-String -TemplateContent "{[int]NameTmp:12}" | ` # Converts string to number and names the variable "NameTmp"
Add-Member -Name "Name" -Value { $this.NameTmp + 1 } -MemberType ScriptProperty -PassThru | ` # Increments variable "NameTmp" by one and adds new variable named "Name" to pipeline object
New-Item -Type Directory # Creates new directy in current folder. Takes directory name from pipelined "Name" variable

Answer 6

Once you have selected the highest value, which is "12" in my example, you can then declare it as integer and increment your value:
$FileList = "1", "2", "11"
$foldername = [int]$FileList[2] + 1
$foldername