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Let me give you a demonstration of how you might use arrays.

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So let's begin once again by creating an empty array, $t.

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Now in $t, I'm going to add some elements.

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The first thing I'm going to add are three random numbers between 0 and 10,

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and I'm using the Get‑Random cmdlet.

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The results of Get‑Random will be added to the array.

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Here I've created an array, $c, which is a collection of characters.

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And again,

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I'm going to use Get‑Random and get 3 random characters from that array,

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$c, and add it to the array, $t.

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Next I'm going to create a string that's just a random word,

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and I kind of messed with the cases a little bit,

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and you'll see why in a moment.

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Strings can be treated as an array, so every character,

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and I think we've looked at this before,

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can be treated as an array element.

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So if I do $w, and then the index number 0 through 2,

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this will show me the first three elements in the string

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BaNanA that I've treated as an array.

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In fact, there is a method on string objects called ToCharArray,

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which will turn the entire string into an array of characters.

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I'm going to run that ToCharArray method and add the results to the array $t.

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So $t now has numbers, it's got characters, and it has a string.

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I think you can probably see where this is going to go.

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So what's in $t right now, alright, so there are all the elements in $t.

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So I'm going to take $t, and you know what,

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I want to randomize the elements in that array.

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So I'm just going to pipe this to Get‑Random, and I only want 9

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elements from that array. That was saved to $rando, so $rando is an

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array of nine elements from $t, randomly selected.

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Let's join them all together into a new variable, $pass, and

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there is a password that you could use.

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There's an example of how you could use arrays to do a particular task, and

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this is something that you would more likely create a PowerShell function

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around, using this code as a starting point.

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There is a help topic for joining.

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Obviously, you'll want to take a look at that. Next I want to show you a few

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other things here with arrays before we move on. Let's go back and review $t,

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alright, so we see what that looks like. And we know that we can reference

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elements from the array with the index number, so the first element starting at

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0 is 3. That works fine when you have created a variable that is an array and it

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has elements in it, but what if you try to run a command like this, $var, and I

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want index zero.

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Maybe $var was something that I created earlier, maybe I forgot to

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create it, maybe it was created through some other command that was

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supposed to feed results to the variable, but I don't know if there

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is anything in that array.

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So if I try to reference index 0,

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I get an error, because $var has not been created or it's

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empty, so there's nothing in that. Again,

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because I got an error, that's not necessarily a bad thing, but in

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PowerShell 7.0, and this is something that might make more sense to you

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when you are scripting, in PowerShell 7.0 we have a new null related

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operator that you can use to check if an index is null without having an

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error, and this is how it works.

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So I'm going to take my variable name,

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var, and put it in curly braces, and I've got $, curly braces,

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the variable name, and then the question mark, and we saw

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this in the other null operators that we looked at earlier,

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and then the index number zero.

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So this is checking, hey, is index 0 null in $var. Because it's null,

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I get null back and I don't get an error message.

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You could write code like this.

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This is something that we looked at earlier in previous demos.

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So I'm going to run that little null indexing operator and then say,

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hey, if this is null, then write a warning.

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And sure enough,

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I get the warning. Again, this is something that you are more

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likely to use in PowerShell scripting more than necessarily

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interactively in the console.

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The last thing I want to tell you, because people will always ask is,

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hey,

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you showed me about adding things to an array, how do

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I remove an element from an array?

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Well, you can't. Really what you can do is this.

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So let me just create a quick array using the numbers 1 through 10.

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If you want to remove an element from an array,

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you in essence have to rebuild the entire array. So you have to use some

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code to filter out or remove the items that you don't want, and then take

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the items that remain and redefine your array.

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So I'm going to redefine $a by taking $a, which is going to be 1

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through 10, and piping it to where object, and I just want to get

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the numbers that are greater or equal to 6.

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Those numbers then get written to the PowerShell pipeline,

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which is saved to $a. So I've recreated $a, which

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is now the numbers 6 through 10.

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So if you need to remove some elements from an array, this is how you would do it.