Here's a few basics that I'm aware of that make things easier for me when I play around with PowerShell.
PowerShell variables all start with a dollar ($) sign.
Initializing a variable requires simply giving it a name, followed by an equals (=) and the value
$myVar = 1
If you want to initialize a variable to multiple values, eg. an array of numbers, you simply comma delimit it
$myVar = 1,2,3
You can also set one variable to another
$myNewVar = $var
Displaying Variable Values
To display the value of a variable, just put in the dollar variable name.
This will show the value of that variable.
If you variable is an array of values, and you want a specific value, then you use square brackets after the variable name, and insert an index in to the brackets. NOTE: PowerShell is indexing starts at zero (0). So the first index into your array is at position 0.
This will give you the second value in your variable array. Since we initialized $myVar to 1,2,3 before, $myVar will return the value 2.
Iterate through each value in an Array Variable
To go through each value in an array variable, you can use a foreach. Similar to the For Each action in Nintex Workflow.
Using the example above, where we have an array variable ($myVar = 1,2,3).
foreach ($var in $myVar)
This will go through each value in $myVar and with each iteration, will store the value in a new temporary variable called $var. Inside the ForEach, I'm simply displaying the value of $var.
If you are doing this in the SharePoint Management Shell, after the final }, press [enter] twice, and it will run the whole foreach you just typed in.
>> PowerShell Basic Basics 102 - SharePoint