打印出核心数

Question

I want to print out the number of cores.

$N_cores = Get-WmiObject –class Win32_processor | ft NumberOfCores 
Write-Host $N_cores | Select-Object -Property NumberOfCores

This give me following:

Microsoft.PowerShell.Commands.Internal.Format.FormatStartData Microsoft.PowerShell.Commands.Internal.Format.GroupStartData Mi
crosoft.PowerShell.Commands.Internal.Format.FormatEntryData Microsoft.PowerShell.Commands.Internal.Format.GroupEndData Micros
oft.PowerShell.Commands.Internal.Format.FormatEndData

How can I display the NumberOfCores?

Answer 1

you need to extract just the value of the cores, try this

$N_cores = Get-WmiObject –class Win32_processor | Select-Object -ExpandProperty NumberOfCores

Write-Host "Number of cores is: $N_cores"

Answer 2

The confusing ouput you're seeing comes from ft (alias for Format-Table ).

To trim the number of properties you want from Get-WmiObject , use Select-Object instead.

For example, to store the NumberOfCores property in $N_cores , and subsequently display only its raw value you could do:

# This will create an object with a `NumberOfCores` property
$N_cores = Get-WmiObject –class Win32_processor |Select-Object NumberOfCores 

# print just the value of the property
Write-Host $N_cores.NumberOfCores

Answer 3

There's a few issues here

1. You are calling Format-Table Format-Table returns an output of format objects
2. You are Piping your Write-Output to Select-Object, which is generally not how you want to got about this...

I suggest you follow the best practice of Filter Left, Format Right

When you pass those objects into the pipe to another function, that function attempt to interpret those objects, if you pass format object to the select-object function it no-longer has the NumberOfCores property.

Ultimately the code that you would want is

`$N_cores = Get-WmiObject –class Win32_processor | Select-Object -Property NumberOfCores
`Format-Table $N_cores |Write-Host

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It should also be mentioned that if you intend to do anything with this script besides print to the console, you should not use Format-Table or Write-Host, instead use `Write-Output $N_cores as your second line. This will write the result not only to the console, but also pass the objects in the $N_cores variable to the pipeline Write-Host vs Write-Output