There are times where you need to know if the object you are working with is an array. There is an easy way to check: use the GetType method. Try the following command:

(Get-ChildItem).GetType()

You can see that it has a BaseType of System.Array. You can use the BaseType to see what type of object you are working with. Also, by adding the property of IsArray to the GetType method you can get a Boolean result whether an object is an array:

(Get-ChildItem).GetType().IsArray

Why is this important? Because different commands can return different types and you may need to code differently based on the type of result you get from a command. Adding a property to an Integer type is different than adding to a Hashtable or an Array.

Here is an excellent explanation of Arrays by Kevin Marquette if you would like to learn more.