1 00:00:00,040 --> 00:00:02,590 So let's go back into the PowerShell console, 2 00:00:02,590 --> 00:00:06,040 and we'll create a function within a PowerShell script. 3 00:00:06,040 --> 00:00:10,380 We'll then make another function with parameters within the PowerShell script. 4 00:00:10,380 --> 00:00:13,780 And then we'll look at how we tie it together and create the basic script. 5 00:00:13,780 --> 00:00:16,530 And then, of course, we'll also execute those as well. 6 00:00:16,530 --> 00:00:20,120 Okay, so after all the things that we've gone through, 7 00:00:20,120 --> 00:00:23,220 the most important thing now is to look at how we construct these 8 00:00:23,220 --> 00:00:26,630 into a script of some description and actually start to use 9 00:00:26,630 --> 00:00:28,290 functions the way that they are intended. 10 00:00:28,290 --> 00:00:32,870 Now, of course, one of the ones that we looked at earlier was this approach here, 11 00:00:32,870 --> 00:00:37,500 the ability for us to use a parameter and then obviously pass various 12 00:00:37,500 --> 00:00:40,670 things to it in order for that function to actually execute. 13 00:00:40,670 --> 00:00:43,550 Now what I've got here are a couple of $outputPaths and $paths, 14 00:00:43,550 --> 00:00:45,870 so I'm actually going to right‑click these variables, Run 15 00:00:45,870 --> 00:00:48,800 Selection, and that will just make sure those are there. 16 00:00:48,800 --> 00:00:51,870 And then I'm just going to kind of scroll that down a little bit here 17 00:00:51,870 --> 00:00:55,440 so it's out of the way. Now what I want to do is kind of talk about 18 00:00:55,440 --> 00:01:01,480 some different ways that we can kind of create functions and classes 19 00:01:01,480 --> 00:01:03,740 and things that we can execute. 20 00:01:03,740 --> 00:01:04,250 Now, of course, 21 00:01:04,250 --> 00:01:09,970 the first thing here is to look at how we get interaction with individual users. 22 00:01:09,970 --> 00:01:12,560 So what I'm going to do is leave the PowerShell kind of 23 00:01:12,560 --> 00:01:14,710 Visual Studio Code open for a second, 24 00:01:14,710 --> 00:01:17,850 and I'm going to launch Windows Terminal again, so as administrator, 25 00:01:17,850 --> 00:01:22,560 run that. Wait for that to load and just clear that one. 26 00:01:22,560 --> 00:01:25,940 And then, of course, I'm going to make sure that we're using PowerShell 7. 27 00:01:25,940 --> 00:01:27,960 So let's just clear that message here. 28 00:01:27,960 --> 00:01:29,440 And then we're good to go. 29 00:01:29,440 --> 00:01:34,540 And what I'm going to do is just paste a function directly into this one. 30 00:01:34,540 --> 00:01:38,500 And what you can see is the function is called Get‑Answer. I actually have 31 00:01:38,500 --> 00:01:41,670 some funny characters so I'll probably have to do that again in a second. But, 32 00:01:41,670 --> 00:01:45,380 basically, there's a question called Read‑Host "What is the Capital City of 33 00:01:45,380 --> 00:01:50,050 Australia?" And then we're combining it with an if statement and some colors 34 00:01:50,050 --> 00:01:51,740 and a few other bits and pieces. 35 00:01:51,740 --> 00:01:56,580 So let me just clear that, and I'll just remove the extra characters. 36 00:01:56,580 --> 00:02:02,310 That is an important thing to kind of remember is that often when you're copying 37 00:02:02,310 --> 00:02:05,910 and pasting things around from other kinds of applications, 38 00:02:05,910 --> 00:02:10,040 you may end up with extra characters that don't really make any sense. 39 00:02:10,040 --> 00:02:11,060 Okay, so we have them in. 40 00:02:11,060 --> 00:02:13,400 So what I'll do now is just enter that. 41 00:02:13,400 --> 00:02:16,050 So we're thinking about building a PowerShell script. 42 00:02:16,050 --> 00:02:22,670 We want some user interaction, so I'm going to say Get‑Answer and just Enter. 43 00:02:22,670 --> 00:02:27,130 And, of course, instantly it provides the user the ability to type something. 44 00:02:27,130 --> 00:02:32,150 So I'm going to say Sydney and Enter, and it will say, 45 00:02:32,150 --> 00:02:36,210 Incorrect!! You entered (the value you typed) which is incorrect, 46 00:02:36,210 --> 00:02:39,000 please try again. So I'm going to try again. 47 00:02:39,000 --> 00:02:43,490 And, of course, as everybody knows, the actual capital is Canberra. 48 00:02:43,490 --> 00:02:48,140 And of course, it says, Correct!! You entered (the value). So a simple approach. 49 00:02:48,140 --> 00:02:51,090 But you can have a PowerShell script that literally uses 50 00:02:51,090 --> 00:02:53,710 what's called, if I just select this here, 51 00:02:53,710 --> 00:02:59,540 Read‑Host and will ask the end user for some kind of interaction. 52 00:02:59,540 --> 00:03:02,090 Now that's a great way of doing it. 53 00:03:02,090 --> 00:03:06,240 But what about if we wanted to be able to pass those values 54 00:03:06,240 --> 00:03:08,650 maybe as part of the function instead? 55 00:03:08,650 --> 00:03:13,040 So I'm now just going to copy and paste another one in. 56 00:03:13,040 --> 00:03:14,240 So here it is. 57 00:03:14,240 --> 00:03:16,910 It's the same principle again, so get the answer. 58 00:03:16,910 --> 00:03:21,570 And this time it will say $question = Read‑Host "Hi (something). 59 00:03:21,570 --> 00:03:24,910 What is the Capital City in Australia?" And then, 60 00:03:24,910 --> 00:03:26,440 of course, it has the same thing. 61 00:03:26,440 --> 00:03:29,510 Now notice we're using something different, and we used this previously. 62 00:03:29,510 --> 00:03:32,830 So we're using what's called arguments, though, in this instance, 63 00:03:32,830 --> 00:03:36,680 we're expecting the end user to type something. So I can say 64 00:03:36,680 --> 00:03:43,210 Get‑Answer "Liam Cleary" and Enter. And it will say, Hi Liam 65 00:03:43,210 --> 00:03:47,530 Cleary, what is the Capital City in Australia? And then because 66 00:03:47,530 --> 00:03:51,010 I already know the answer, I can say Canberra, and it gives me the value. 67 00:03:51,010 --> 00:03:53,200 So, once again, a different way, 68 00:03:53,200 --> 00:03:57,250 it's still utilizing the Read‑Host option for the end user to provide 69 00:03:57,250 --> 00:03:59,900 information or the admin to provide information. 70 00:03:59,900 --> 00:04:03,240 However, what it's doing is making it more personal. 71 00:04:03,240 --> 00:04:06,410 Now, of course, we know that we could go a little step further here, 72 00:04:06,410 --> 00:04:13,240 and we could change that from using an argument to actually using a variable. 73 00:04:13,240 --> 00:04:16,770 So you can see here we've got the same kind of function again, 74 00:04:16,770 --> 00:04:20,440 so we're going to say Get‑Answer. 75 00:04:20,440 --> 00:04:23,050 And this time it requires a name. 76 00:04:23,050 --> 00:04:27,430 So I'm going to say in quotes (can't even spell my own 77 00:04:27,430 --> 00:04:31,490 name) "Liam Cleary" Enter. And it will say, 78 00:04:31,490 --> 00:04:32,110 Hi, Liam. 79 00:04:32,110 --> 00:04:35,040 What's the Capital City? 80 00:04:35,040 --> 00:04:37,140 Canberra, and correct. 81 00:04:37,140 --> 00:04:38,400 So a couple different ways. 82 00:04:38,400 --> 00:04:39,640 We used arguments. 83 00:04:39,640 --> 00:04:41,330 We used Read‑Host. 84 00:04:41,330 --> 00:04:43,250 We used a combination of those two. 85 00:04:43,250 --> 00:04:46,440 Plus, we changed it to use a variable. 86 00:04:46,440 --> 00:04:48,780 Now what about if we want to go a little step further? 87 00:04:48,780 --> 00:04:53,030 We want to be able to provide a series of values so that 88 00:04:53,030 --> 00:04:55,180 the end user can just kind of pick. 89 00:04:55,180 --> 00:04:56,470 Now that would make more sense. 90 00:04:56,470 --> 00:05:01,640 Now that helps us by restricting it to specific values. 91 00:05:01,640 --> 00:05:04,200 It stops people spelling things incorrectly. 92 00:05:04,200 --> 00:05:06,690 And it also means that from a code perspective, 93 00:05:06,690 --> 00:05:10,540 we already know what the answers are that we should be expecting. 94 00:05:10,540 --> 00:05:14,140 So I'm now just going to copy and paste another one in. 95 00:05:14,140 --> 00:05:14,970 So here we are. 96 00:05:14,970 --> 00:05:16,210 This is a new function. 97 00:05:16,210 --> 00:05:21,140 It's called Test‑WhatIsCapitalCityofAustralia. So we've removed the question. 98 00:05:21,140 --> 00:05:23,970 We've put that into the function. And then you'll see we've got 99 00:05:23,970 --> 00:05:28,830 this Param section here where we've said go and get the parameter, 100 00:05:28,830 --> 00:05:32,850 so provide one as a mandatory one called $city. And then we have 101 00:05:32,850 --> 00:05:37,020 what's called ValidateSet, which provides four specific options. 102 00:05:37,020 --> 00:05:40,270 So what does that look like for the person executing this? 103 00:05:40,270 --> 00:05:46,040 So I'm going to say Test‑WhatIsCapitalCityofAustralia. Then I 104 00:05:46,040 --> 00:05:48,410 can do a tab here, and you'll see ‑city. 105 00:05:48,410 --> 00:05:53,120 And then when I tab, it lets me loop through the various options. 106 00:05:53,120 --> 00:05:56,190 So if I choose Melbourne, it's going to say Incorrect. 107 00:05:56,190 --> 00:05:59,930 If I go back here, try Canberra, I get the correct value. 108 00:05:59,930 --> 00:06:06,830 So, again, we change the input of the script to then have a predetermined 109 00:06:06,830 --> 00:06:11,740 list of values so that it makes life a little bit easier. 110 00:06:11,740 --> 00:06:15,850 Now, of course, there are lots of other ways of interacting with scripts. 111 00:06:15,850 --> 00:06:19,140 So let's go back to Visual Studio Code, 112 00:06:19,140 --> 00:06:23,580 and what we can see here is I've got some other options available to us. So you 113 00:06:23,580 --> 00:06:27,210 can see I'm creating what's called an Autocomplete option, 114 00:06:27,210 --> 00:06:28,970 which contains all the values. 115 00:06:28,970 --> 00:06:32,610 Now what I wanted to do here is I wanted to use the same 116 00:06:32,610 --> 00:06:35,110 mechanism that we had before where we're saying, What's the 117 00:06:35,110 --> 00:06:37,650 Capital City, and providing some values. 118 00:06:37,650 --> 00:06:40,540 But I wanted those values to come from somewhere else. 119 00:06:40,540 --> 00:06:46,250 So maybe from an array or maybe a JSON file or maybe an XML. 120 00:06:46,250 --> 00:06:50,140 So what we can do, I'm going to slide this over here, is you 121 00:06:50,140 --> 00:06:52,330 can see we can create what's called a class. 122 00:06:52,330 --> 00:06:54,720 So inside the PowerShell script, 123 00:06:54,720 --> 00:06:58,640 we create a class for the definition of the content. 124 00:06:58,640 --> 00:07:04,380 So, for example, this one is an IValidateSetValuesGenerator. 125 00:07:04,380 --> 00:07:09,450 What that means is it's going to create a list of values, and it can be dynamic. 126 00:07:09,450 --> 00:07:13,780 So at the moment I have static values typed into an array. 127 00:07:13,780 --> 00:07:17,250 But that could be a JSON call, an XML call, a web 128 00:07:17,250 --> 00:07:19,540 service call, whatever it would be. 129 00:07:19,540 --> 00:07:20,980 So I have this class. 130 00:07:20,980 --> 00:07:24,590 I've defined it as a string called GetValidValues. And 131 00:07:24,590 --> 00:07:26,570 then I can return a city object. 132 00:07:26,570 --> 00:07:29,720 So I'm going to execute that command. That will then 133 00:07:29,720 --> 00:07:33,340 populate here ready for me to use it. 134 00:07:33,340 --> 00:07:38,140 So this $Cities option should be valid now for me to use. 135 00:07:38,140 --> 00:07:41,750 Now what we can do is like we did with the Australia one, I 136 00:07:41,750 --> 00:07:44,300 want to somehow test the population of Hawaii. 137 00:07:44,300 --> 00:07:48,630 So I've created a function, and you can see how Visual Studio Code is 138 00:07:48,630 --> 00:07:52,240 great at rendering this, color coding the whole thing. 139 00:07:52,240 --> 00:07:53,520 So what I've done here, 140 00:07:53,520 --> 00:07:57,710 the different line is this one where the ValidateSet instead of 141 00:07:57,710 --> 00:08:00,440 it being an array of values that we type, 142 00:08:00,440 --> 00:08:04,920 it's actually calling into that specific class called Cities, 143 00:08:04,920 --> 00:08:06,440 which is listed here. 144 00:08:06,440 --> 00:08:13,040 So if I was to go ahead and just select this function and then go Run Selection, 145 00:08:13,040 --> 00:08:14,740 so now we have it. 146 00:08:14,740 --> 00:08:22,290 Now I can say Test‑PopulationOfHawaii, and then it finds the property ‑Answer, 147 00:08:22,290 --> 00:08:23,340 which is the variable. 148 00:08:23,340 --> 00:08:24,970 And then if I just tab, 149 00:08:24,970 --> 00:08:32,110 we're getting numbers now. If I just go back here, 1.4, 2 million, 500 Thousand, 150 00:08:32,110 --> 00:08:34,790 750 Thousand. So no specific order. 151 00:08:34,790 --> 00:08:36,930 But it means that I can go through and select. 152 00:08:36,930 --> 00:08:40,340 If I choose Enter, it tells me it's incorrect. 153 00:08:40,340 --> 00:08:43,330 If I go back here, say 1.4, it tells me it's correct. 154 00:08:43,330 --> 00:08:45,470 So very similar to what we did before, 155 00:08:45,470 --> 00:08:49,200 but notice we have the flexibility now of really starting 156 00:08:49,200 --> 00:08:52,770 to create something that's quite powerful. So I can store 157 00:08:52,770 --> 00:08:57,950 information in a database, for example, and still query it using PowerShell. 158 00:08:57,950 --> 00:09:01,640 And then, of course, I can wrap that into functions as well. 159 00:09:01,640 --> 00:09:06,140 Okay, so let me just clear the bottom section here and drag down. 160 00:09:06,140 --> 00:09:08,870 Now we can also go a little bit further as well. 161 00:09:08,870 --> 00:09:12,360 We can start to create functions that would allow us to 162 00:09:12,360 --> 00:09:16,190 add things together, to delete things, whatever it would be. 163 00:09:16,190 --> 00:09:20,840 You can see here I've got a function called MathAnswer, 164 00:09:20,840 --> 00:09:24,740 which takes in two properties called $numberOne and $numberTwo, 165 00:09:24,740 --> 00:09:25,950 which will be numbers. 166 00:09:25,950 --> 00:09:29,350 It also takes a $mathOperator, which is going to be a plus, 167 00:09:29,350 --> 00:09:34,080 a minus, a divide, or a multiply, a ValidateSet, 168 00:09:34,080 --> 00:09:36,240 which is a value that we can utilize. 169 00:09:36,240 --> 00:09:41,240 So if someone says Add, then, of course, it will go ahead and do that. 170 00:09:41,240 --> 00:09:43,180 I can then go in and say, Well, hey, 171 00:09:43,180 --> 00:09:46,240 the $mathOperator that you chose was this one, 172 00:09:46,240 --> 00:09:48,090 and I could then use that. 173 00:09:48,090 --> 00:09:51,240 But you'd also see that I'm using the ValidateSet too. 174 00:09:51,240 --> 00:09:55,640 So if the $mathOperator is equal to the word Add, 175 00:09:55,640 --> 00:10:00,200 then it's going to run through here, and it's going to say Invoke‑AddNumbers. 176 00:10:00,200 --> 00:10:02,490 Now where does Invoke‑AddNumbers come from? 177 00:10:02,490 --> 00:10:05,040 Well, there are a series of separate functions that are 178 00:10:05,040 --> 00:10:11,620 listed here. So each of these functions are available and 179 00:10:11,620 --> 00:10:14,360 can be called by the main function. 180 00:10:14,360 --> 00:10:15,760 So what does this look like? 181 00:10:15,760 --> 00:10:20,700 Well, the beauty here is we can select everything that's here. 182 00:10:20,700 --> 00:10:24,680 So let me go to Function Get‑MathAnswer all the way down to here, 183 00:10:24,680 --> 00:10:27,040 and we'll just execute everything. 184 00:10:27,040 --> 00:10:28,980 Now what does the execute mean? 185 00:10:28,980 --> 00:10:33,440 It actually loads it into memory, so we can then use it. 186 00:10:33,440 --> 00:10:37,700 So now that we've executed it and it's in memory, how do we actually run that? 187 00:10:37,700 --> 00:10:40,240 Well, let me just clear the bottom section here. 188 00:10:40,240 --> 00:10:42,240 And if we scroll all the way back up, 189 00:10:42,240 --> 00:10:49,040 we can actually call Get‑MathAnswer as the function, so Get‑MathAnswer. 190 00:10:49,040 --> 00:10:51,120 And then, of course, I get a property called ‑numberOne. 191 00:10:51,120 --> 00:10:56,030 So let's call that 10. And then I should get another one called ‑numberTwo. 192 00:10:56,030 --> 00:10:58,850 So let's call that 5. And then there'll be another one 193 00:10:58,850 --> 00:11:02,790 called ‑mathoperator. And I can tab through. 194 00:11:02,790 --> 00:11:05,560 So if I say Multiply and do Enter, 195 00:11:05,560 --> 00:11:11,040 it will say Math Operator was Multiply, and the answer is 50. 196 00:11:11,040 --> 00:11:15,890 If I change that and say, Add, you can see 15. So notice what we did here. 197 00:11:15,890 --> 00:11:17,740 We're building the script. 198 00:11:17,740 --> 00:11:21,920 The goal is to build as many things into functions as 199 00:11:21,920 --> 00:11:25,570 possible so that then, when you run the script, 200 00:11:25,570 --> 00:11:29,540 it will execute the various commands that you need. Now how you build 201 00:11:29,540 --> 00:11:32,740 them, let me just close this here, is entirely up to you. 202 00:11:32,740 --> 00:11:36,630 Best practice is obviously declaring variables at the top section and then 203 00:11:36,630 --> 00:11:41,430 any functions and then call any of the functions later on. 204 00:11:41,430 --> 00:11:43,740 So what we can do here, for example, 205 00:11:43,740 --> 00:11:50,540 is because we have a list of functions is we can actually say function Begin. 206 00:11:50,540 --> 00:11:52,300 We could call it something like this. 207 00:11:52,300 --> 00:11:55,740 And then what we can do is, 208 00:11:55,740 --> 00:12:00,480 let's say we're going to say Test‑PopulationOfHawaii, and, you know, that's 209 00:12:00,480 --> 00:12:03,190 going to be the function I'm going to call. And then I'm going to say 210 00:12:03,190 --> 00:12:08,380 Get‑MathAnswer, and maybe that's going to be a function. 211 00:12:08,380 --> 00:12:13,340 And then what we do is we then call Begin. 212 00:12:13,340 --> 00:12:16,520 I actually don't want‑‑‑we can use &, but I'm just going to say Begin for now. 213 00:12:16,520 --> 00:12:20,300 So what that means is, when the script runs, 214 00:12:20,300 --> 00:12:23,240 it will automatically call a function, 215 00:12:23,240 --> 00:12:27,410 and then the function will then call everything else that's needed. Now, 216 00:12:27,410 --> 00:12:32,300 what I would suggest with you is that you somehow either have these so the 217 00:12:32,300 --> 00:12:38,130 end user has to provide the variable values or you obviously have it so 218 00:12:38,130 --> 00:12:40,550 they have to put them in manually into the file. 219 00:12:40,550 --> 00:12:43,340 It really depends on what you're trying to achieve. There 220 00:12:43,340 --> 00:12:45,840 are multiple different ways of doing it. 221 00:12:45,840 --> 00:12:53,000 The key, though, is use the building blocks, use the PowerShell functions, use the variables, and tie them all together.