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PowerShell via .NET is full of different types of objects.

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Now these are some of the most common ones you'll come across. A string

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is just text. The int, the i‑n‑t that you see there, is an integer,

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although you'll also see sometimes Int32 or Int64, which technically and

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in .NET terms is something different.

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But for our purposes, we're just going to treat them all as numbers.

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DateTime should be self explanatory. And a Boolean is true or false.

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In PowerShell, you'll use the Boolean variables $true and $false.

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Now how can you discover what type of an object something is or what that

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object looks like in terms of its properties and methods?

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Well for that, we're going to use the Get‑Member cmdlet.

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This cmdlet has an alias of gm,

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which you'll use often, and you'll see it a lot in the wild.

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Like help and Get‑Command, this is one of the most critical

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cmdlets for you to learn and use often.

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This is a key discovery command.

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One of the reasons that this matters to you is that often

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you'll need to discover the rest of the story. When you

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run a command in PowerShell,

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don't assume that the output that you see is all there is.

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PowerShell often has a defined default view of different object types,

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which almost never shows you, or almost never shows

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you, all of the possible properties.

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And in some cases,

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PowerShell will use custom names to make the output more meaningful to you.

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PowerShell tries to help you and abstract things from you.

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Don't assume that what you see is all there is. And this will

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become much clearer in the demonstration.

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You need to be able to identify other properties because you'll be learning

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and using cmdlets that will be able to use any property that you can

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identify with Get‑Member. Think of Get‑Member as the authoritative source

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for all information relating to an object.

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And this can also help you. Not getting a result you expect when you run a

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command? Rerun the command and pipe the results to Get‑Member to identify

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what's coming out of the pipeline. Or, even better,

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drop the last part of your pipeline expression and

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pipe to Get‑Member. As you'll see, objects can change in the pipeline,

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and you may not be ending up with what you started with.

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So by now, it should be pretty clear to you that when you run a

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PowerShell command it sends objects down the pipeline.

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Although this isn't a locked‑in requirement,

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you'll find plenty of code samples in the wild. And in the wild,

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I mean that people have published on blogs and in code libraries

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and GitHub and that sort of thing.

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You'll find plenty of samples where people are using Write‑Host.

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And they're using Write‑Host to omit the output,

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which, as we saw in the last module,

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sends output to the hosting application and not the pipeline.

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These types of commands should be considered the exception and not the rule.

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You'll also come across commands that don't write an object to the

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pipeline because, you know, it just doesn't make sense.

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If you kill a process,

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the Stop‑Process command, by default, doesn't write anything to

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the pipeline. And there's really no reason to. The process is gone

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so what are you going to do with it?

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Still, if you look at the Stop‑Process help, you'll see a ‑PassThru parameter.

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Now if you use this parameter, the cmdlet, in this case Stop‑Process, will

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write the object to the pipeline that it was working with.

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This might be useful if you are using Stop‑Process in a

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situation where you want to run the command and then send it

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to something to create an audit trail.

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Whenever you see ‑PassThru in the help for a command, that is

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your clue that the command does not write anything to the

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pipeline so you can't pipe anything from that command to

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something else unless you use ‑PassThru.

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Now of course what makes PowerShell easy is that you can join commands together.

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Some commands are designed to accept or consume objects.

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These commands may be designed to take an entire object,

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or they may use properties of an incoming object.

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Very often when you see a Get‑Command there'll be one or more

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corresponding commands to do something with it.

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So, Get‑Service has related commands to let you set,

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stop, start, and restart a service.

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You can get a bunch of services that meet some criteria and

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then pipe them to something like Restart‑Service. Again,

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there's no cryptic scripting.

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It's a relatively simple PowerShell expression.

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I always try to get people to think about this idea of managing at scale.

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And this may make more sense when you get to scripting.

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If you can do something for one object,

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you can probably do the same thing to 100 or 1000 objects.

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Don't think about doing something or writing a command to do one thing.

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Think about how would I write it to do something for all things or 100 things. The PowerShell pipeline is what makes this possible.