1 00:00:00,040 --> 00:00:02,230 So let's go back into the PowerShell console. 2 00:00:02,230 --> 00:00:05,060 We'll create a custom data object. 3 00:00:05,060 --> 00:00:08,400 We'll first also retrieve data from the custom object by 4 00:00:08,400 --> 00:00:10,770 loading and reusing that custom object. 5 00:00:10,770 --> 00:00:14,260 We'll then test those objects using that ‑IS operator. 6 00:00:14,260 --> 00:00:19,380 Now, PowerShell provides us the ability for using custom data, 7 00:00:19,380 --> 00:00:23,310 different types of data that we can store or retrieve. 8 00:00:23,310 --> 00:00:28,340 Now, the easiest example here would be to create a new variable, 9 00:00:28,340 --> 00:00:35,300 and we can use the @ and the brackets here to actually create an array, 10 00:00:35,300 --> 00:00:37,020 and that's effectively an empty array. 11 00:00:37,020 --> 00:00:40,390 So if I say variable, and just do this, 12 00:00:40,390 --> 00:00:43,630 there'll be no values that are associated to that. 13 00:00:43,630 --> 00:00:48,170 Now, if I wanted to change that and actually utilize values, 14 00:00:48,170 --> 00:00:51,850 then we can simply use text values here, 15 00:00:51,850 --> 00:01:05,740 so Jan, Feb, Mar, Apr, May, and Jun. 16 00:01:05,740 --> 00:01:11,270 Okay, now we can say $variable, and we get our values back, 17 00:01:11,270 --> 00:01:14,140 so it's an array of those objects. 18 00:01:14,140 --> 00:01:18,270 Now, that's a standard array with text values. 19 00:01:18,270 --> 00:01:21,510 Now, we've also created arrays already, 20 00:01:21,510 --> 00:01:27,310 where we've actually created an array by not using the definition of an array, 21 00:01:27,310 --> 00:01:31,750 but by adding the values in like this, which works perfectly fine, 22 00:01:31,750 --> 00:01:33,460 so that's one way of doing it too. 23 00:01:33,460 --> 00:01:37,540 You don't have to declare by using @ and brackets every 24 00:01:37,540 --> 00:01:39,940 time you want to create an array. 25 00:01:39,940 --> 00:01:43,080 However, what that does give us is, 26 00:01:43,080 --> 00:01:46,320 if we just go back here and create the empty array, 27 00:01:46,320 --> 00:01:50,950 is that when we say variable.Add, 28 00:01:50,950 --> 00:01:55,940 we get this kind of function method that's available to us to add entries to it, 29 00:01:55,940 --> 00:01:59,240 whereas if we've created the variable without that, 30 00:01:59,240 --> 00:02:00,470 we don't have that flexibility, 31 00:02:00,470 --> 00:02:04,600 so there is a reason for creating them that way as well. 32 00:02:04,600 --> 00:02:07,250 So let's just go back here and populate that with some values, 33 00:02:07,250 --> 00:02:09,440 okay, so now we have that. 34 00:02:09,440 --> 00:02:12,090 Now, if we want to access the data in here, 35 00:02:12,090 --> 00:02:16,230 you can see that we could just type the variable and it would output the values. 36 00:02:16,230 --> 00:02:19,420 But, of course, as with all sets of data, 37 00:02:19,420 --> 00:02:22,720 we do have the ability to utilize an offset. 38 00:02:22,720 --> 00:02:24,760 So, for example, if I use 0, 39 00:02:24,760 --> 00:02:27,210 that's the first piece that was chopped out in the array, 40 00:02:27,210 --> 00:02:29,650 I get February, sorry, January. 41 00:02:29,650 --> 00:02:36,140 If I do 2, then I'll get March, because, remember, it starts at 0, not at 1. 42 00:02:36,140 --> 00:02:39,610 It also means that I can do this, too. 43 00:02:39,610 --> 00:02:45,190 I can then use different values to be able to retrieve those items from there. 44 00:02:45,190 --> 00:02:50,520 So 0, which is January, 1 is February, 4 would be May, 45 00:02:50,520 --> 00:02:52,890 for example, so I get those values back. 46 00:02:52,890 --> 00:02:57,100 We also have the ability to use, so 0..3, 47 00:02:57,100 --> 00:03:02,640 so using that range operator that we used previously for adding data, 48 00:03:02,640 --> 00:03:06,600 we can use that for retrieving values as well, 49 00:03:06,600 --> 00:03:11,540 so really simple kind of ways of accessing the data. 50 00:03:11,540 --> 00:03:15,980 Now, what's nice is once the data is in a variable, 51 00:03:15,980 --> 00:03:20,230 then of course we can retrieve the data either that way or 52 00:03:20,230 --> 00:03:22,650 we can retrieve it by piping the values. 53 00:03:22,650 --> 00:03:26,870 Now a pipe option allows us to take the values or something 54 00:03:26,870 --> 00:03:30,140 from a command and pass it into the next one. 55 00:03:30,140 --> 00:03:32,460 So I'm going to use something that we've already talked about, 56 00:03:32,460 --> 00:03:34,010 which is called ForEach‑Object. 57 00:03:34,010 --> 00:03:37,740 So I'm going to say take everything that's in the variable, 58 00:03:37,740 --> 00:03:42,900 and for every single one of those, in my script block I want it to do something. 59 00:03:42,900 --> 00:03:47,040 So I'm going to go in and say Write‑Host. 60 00:03:47,040 --> 00:03:54,330 So I'm going to write a value and say The month is, 61 00:03:54,330 --> 00:03:58,640 and then I can say $, I missed my letters there, 62 00:03:58,640 --> 00:04:02,120 PSItem, and close that off. 63 00:04:02,120 --> 00:04:06,740 Now, PSItem is a value that's returned from the ForEach‑Object. 64 00:04:06,740 --> 00:04:09,780 And, of course, when I enter that, that's what it does, 65 00:04:09,780 --> 00:04:12,440 the PSItem is an arbitrary one that's there, 66 00:04:12,440 --> 00:04:15,840 that when you use ForEach‑Object, that's what comes back. 67 00:04:15,840 --> 00:04:19,310 So now I can say, hey, here's my variable of data, 68 00:04:19,310 --> 00:04:22,400 for each item in there, iterate it, and then do something, 69 00:04:22,400 --> 00:04:25,800 and in this instance I'm writing out values to the screen. 70 00:04:25,800 --> 00:04:27,910 So that's one way of doing that. 71 00:04:27,910 --> 00:04:30,850 The second way of doing that is to use the trusty old 72 00:04:30,850 --> 00:04:38,340 foreach statement that we used before, where I can say $item in $variable, 73 00:04:38,340 --> 00:04:41,310 and then do the same thing as we did before, 74 00:04:41,310 --> 00:04:44,970 where we kind of output in that inside the script block here. 75 00:04:44,970 --> 00:04:52,070 So Write‑Host, and I'm just going to say $item, like so. 76 00:04:52,070 --> 00:04:55,760 And, of course, you get January all the way to June, so nice and easy. 77 00:04:55,760 --> 00:04:59,940 So we can use all of the different looping mechanisms that we 78 00:04:59,940 --> 00:05:03,070 used previously to actually get the data back, 79 00:05:03,070 --> 00:05:09,180 which is really the most common thing that you would do with data that you get. 80 00:05:09,180 --> 00:05:13,540 You want to iterate through it, and you want to do something with it. 81 00:05:13,540 --> 00:05:17,500 Now, an array is great, but really it's just a single value, 82 00:05:17,500 --> 00:05:20,210 well, I say single values, but it's multiple values, 83 00:05:20,210 --> 00:05:22,620 but there's just a single value for each one. 84 00:05:22,620 --> 00:05:27,400 So we can also create data, so I'm going to call it variableh, 85 00:05:27,400 --> 00:05:32,740 and then I'm going to say @ and I'm going to use squirrely brackets this time. 86 00:05:32,740 --> 00:05:36,470 Now notice that's not an array this time, that's a hash table. 87 00:05:36,470 --> 00:05:42,670 Now a hash table is a series of keys and values, so let me give you an idea. 88 00:05:42,670 --> 00:05:48,820 So I've got my variableh even, and from here I can say @, 89 00:05:48,820 --> 00:05:51,100 squirrely brackets instead of the regular, 90 00:05:51,100 --> 00:05:59,540 and then I'm going to say Month=5, Name=May, 91 00:05:59,540 --> 00:06:01,780 Season=Spring. 92 00:06:01,780 --> 00:06:07,020 So let's put some of these in quotes, 93 00:06:07,020 --> 00:06:09,520 because they're string values that we need to return back, 94 00:06:09,520 --> 00:06:12,940 so let's do this, and let's do that. 95 00:06:12,940 --> 00:06:15,490 Okay, now notice what happened here. 96 00:06:15,490 --> 00:06:20,820 It says that I have some syntax errors, and that's great, 97 00:06:20,820 --> 00:06:24,330 because what that means is that notice how we would 98 00:06:24,330 --> 00:06:27,910 normally comma separate things, we actually, 99 00:06:27,910 --> 00:06:32,940 when we're doing key‑value pairs, we have to use the semicolon instead. 100 00:06:32,940 --> 00:06:38,460 Now, what that does for us, say if I do variableh and Enter it, 101 00:06:38,460 --> 00:06:41,770 you can see I then get a name and a value, 102 00:06:41,770 --> 00:06:47,040 so Month is 5, Name is May, Season is Spring. 103 00:06:47,040 --> 00:06:49,010 Now, what does that do for us? 104 00:06:49,010 --> 00:06:50,840 Well, let's look at this. 105 00:06:50,840 --> 00:06:54,790 So what we can do is I can say variableh.Count, 106 00:06:54,790 --> 00:06:58,580 and you see I've got all these different things that are there. 107 00:06:58,580 --> 00:07:03,090 I could say Values, and this will go and get me just the values. 108 00:07:03,090 --> 00:07:07,420 Or, I could say get me the Keys, and it gets me the keys. 109 00:07:07,420 --> 00:07:11,470 So you have the ability to store values with a key 110 00:07:11,470 --> 00:07:14,140 that you can then reference later on. 111 00:07:14,140 --> 00:07:18,240 I can also change the order around as well, if I needed to. 112 00:07:18,240 --> 00:07:21,200 Let's think a little bit kind of wider here. 113 00:07:21,200 --> 00:07:23,310 I'm just going to copy something and paste it in, 114 00:07:23,310 --> 00:07:28,230 just because it's easier for the text that I'm using. 115 00:07:28,230 --> 00:07:33,080 So you can see I'm creating a new variable as a hash table and I 116 00:07:33,080 --> 00:07:35,610 have four countries in here with their population, 117 00:07:35,610 --> 00:07:37,540 so I'm going to press Enter here. 118 00:07:37,540 --> 00:07:40,760 Now, what that means is I can go to variable, 119 00:07:40,760 --> 00:07:43,850 and I now get this matrix of a table that basically 120 00:07:43,850 --> 00:07:48,440 says this country has this value, etc. 121 00:07:48,440 --> 00:07:51,740 So how can we retrieve some of this item? 122 00:07:51,740 --> 00:07:54,520 Well, the first option that we've got is like we just did, 123 00:07:54,520 --> 00:08:00,050 we can say variable.Keys, and I get the values of that, 124 00:08:00,050 --> 00:08:03,390 but I don't get the value associated to the keys, 125 00:08:03,390 --> 00:08:07,150 so we need some way of kind of iterating through them. 126 00:08:07,150 --> 00:08:11,460 Now, the simplest way of doing this is to do a foreach statement, 127 00:08:11,460 --> 00:08:15,120 and I can say $key, so that's an empty value, 128 00:08:15,120 --> 00:08:20,540 in, and then I'm going to say variable.Keys. 129 00:08:20,540 --> 00:08:25,360 So what I'm doing is I'm going to iterate through the sets of keys, 130 00:08:25,360 --> 00:08:27,640 and I need to be able to retrieve value. 131 00:08:27,640 --> 00:08:31,140 So I'm now going to create a new variable called output, 132 00:08:31,140 --> 00:08:36,660 and I'm going to use some kind of string manipulation here, 133 00:08:36,660 --> 00:08:42,160 has a population of, and another one of these, 134 00:08:42,160 --> 00:08:44,340 so 1. 135 00:08:44,340 --> 00:08:46,150 So if you've never seen this before, 136 00:08:46,150 --> 00:08:49,200 this is a standard constructing code where you're formatting 137 00:08:49,200 --> 00:08:52,920 a string value and you use the little squirrely brackets 138 00:08:52,920 --> 00:08:55,730 with a number that represents 0, 1, 2, 3, 139 00:08:55,730 --> 00:08:56,860 4, etc. 140 00:08:56,860 --> 00:09:00,630 I'm then going to go in and say for the first value I 141 00:09:00,630 --> 00:09:03,800 want that to be what's called $_, which is the key, 142 00:09:03,800 --> 00:09:09,050 and then the next one is $variable, brackets, 143 00:09:09,050 --> 00:09:11,020 remember, is used for the offset, 144 00:09:11,020 --> 00:09:15,240 but I'm just going to use the identifier piece there and press Enter. 145 00:09:15,240 --> 00:09:22,800 Once I've done that one, then I'm going to say Write‑Output $, 146 00:09:22,800 --> 00:09:29,040 oh, I don't want all of that, I just want the smaller variable. 147 00:09:29,040 --> 00:09:30,370 Let me just change this. 148 00:09:30,370 --> 00:09:32,020 Let me just do Write‑Host instead. 149 00:09:32,020 --> 00:09:35,320 I was trying to write out too much. 150 00:09:35,320 --> 00:09:45,240 (Writing) Output, there we go, and close that out, and Enter. 151 00:09:45,240 --> 00:09:46,850 Now, what happened here? 152 00:09:46,850 --> 00:09:49,430 You can see that I've got loads and loads and loads 153 00:09:49,430 --> 00:09:50,970 of errors all over the place. 154 00:09:50,970 --> 00:09:53,830 It doesn't like what's taken place here. 155 00:09:53,830 --> 00:09:56,940 So let's kind of break this down what it's trying to do. 156 00:09:56,940 --> 00:10:01,740 So what you can see here is we've got a foreach statement, 157 00:10:01,740 --> 00:10:05,770 which is going to go and loop through the values, 158 00:10:05,770 --> 00:10:09,190 and you can see that we're trying to use this $_. 159 00:10:09,190 --> 00:10:11,440 Now hold on a minute, what is a $_? 160 00:10:11,440 --> 00:10:15,410 Well, a $_ is an object that returns back, 161 00:10:15,410 --> 00:10:17,700 yes, wait a minute, I can hear you thinking, 162 00:10:17,700 --> 00:10:24,140 it's like the PSItem, which means it can't be returned in a foreach statement. 163 00:10:24,140 --> 00:10:30,040 So in a foreach statement, we have to use the named objects that come back. 164 00:10:30,040 --> 00:10:33,390 So let's go back through the code, so here's my output, 165 00:10:33,390 --> 00:10:35,390 and we're going to change these values, 166 00:10:35,390 --> 00:10:39,800 because the $_ is only available for a foreach. 167 00:10:39,800 --> 00:10:42,330 So what this is going to be is the key. 168 00:10:42,330 --> 00:10:44,340 Where does the key come from? 169 00:10:44,340 --> 00:10:47,590 From the entry in the beginning of the for loop. 170 00:10:47,590 --> 00:10:52,440 If I then go here and say $key, like so, 171 00:10:52,440 --> 00:10:59,540 I can then say Write‑Host, and I'll just say, 172 00:10:59,540 --> 00:11:03,250 sometimes it's not best to use words that match everything else, 173 00:11:03,250 --> 00:11:05,480 and close that out, and then Enter. 174 00:11:05,480 --> 00:11:06,950 And sure enough, it now works. 175 00:11:06,950 --> 00:11:09,660 It now says Spain has a population of something, 176 00:11:09,660 --> 00:11:13,050 blah, blah, blah, blah, all the way down to India has a population of, 177 00:11:13,050 --> 00:11:13,810 and something. 178 00:11:13,810 --> 00:11:17,760 So It's really important to understand that when you see examples 179 00:11:17,760 --> 00:11:20,580 of PowerShell code that's available to you, 180 00:11:20,580 --> 00:11:23,010 just make sure that you're not mixing and matching. 181 00:11:23,010 --> 00:11:27,370 So aForEach‑Object loop would look very similar, 182 00:11:27,370 --> 00:11:31,160 so let's just kind of show you what that would look like. 183 00:11:31,160 --> 00:11:33,230 I'm not going to run all of it, but show you. 184 00:11:33,230 --> 00:11:39,410 You would do the variable, you would do a ForEach‑Object statement, 185 00:11:39,410 --> 00:11:46,400 like so, and then for this row you would do that same thing that we did, 186 00:11:46,400 --> 00:11:53,340 so 0, some text, 1, close that out. 187 00:11:53,340 --> 00:12:01,360 Then you get access to the _$, and then you can say variable, 188 00:12:01,360 --> 00:12:04,210 in the brackets $_. 189 00:12:04,210 --> 00:12:15,440 Once we have that, Write‑Host $output, and do that, and Enter. 190 00:12:15,440 --> 00:12:18,440 And then, of course, depending if you've got all the variables right, 191 00:12:18,440 --> 00:12:21,930 it'll then write out the variable values that you're expecting. 192 00:12:21,930 --> 00:12:24,990 You noticed why it's come back with a hash table? 193 00:12:24,990 --> 00:12:27,140 Extra points if you can get this right, 194 00:12:27,140 --> 00:12:28,830 but I'm going to give you the answer anyway, 195 00:12:28,830 --> 00:12:34,140 is because the variable that we actually want to iterate is variable.Keys, 196 00:12:34,140 --> 00:12:36,930 not the actual variable itself. 197 00:12:36,930 --> 00:12:40,100 So if we go back here and say Write‑Host and do that, 198 00:12:40,100 --> 00:12:41,740 you'll get all the values now. 199 00:12:41,740 --> 00:12:43,990 So it's really important to understand the definition of 200 00:12:43,990 --> 00:12:46,240 the object that you're trying to get to. 201 00:12:46,240 --> 00:12:48,740 Okay, so let's just clear that for a second. 202 00:12:48,740 --> 00:12:49,450 Now, 203 00:12:49,450 --> 00:12:52,990 one of the last things that we can look at here is really around 204 00:12:52,990 --> 00:12:56,070 creating what's referred to as a custom object. 205 00:12:56,070 --> 00:12:59,500 Now, PowerShell obviously has the PSCustomObject, 206 00:12:59,500 --> 00:13:04,140 and most things get returned as a PSObject. 207 00:13:04,140 --> 00:13:09,640 So I'm just going to copy some code here, and I'm just going to paste over here. 208 00:13:09,640 --> 00:13:12,950 Now you can see the code looks almost identical to the last one, 209 00:13:12,950 --> 00:13:16,420 except the difference is right here we've declared 210 00:13:16,420 --> 00:13:20,060 that object as a PSCustomObject, so we'll just enter that, 211 00:13:20,060 --> 00:13:22,440 so now we have a value. 212 00:13:22,440 --> 00:13:27,580 So if I go back and say variable, notice it lays it out a little bit differently, 213 00:13:27,580 --> 00:13:29,230 but you still get the same values. 214 00:13:29,230 --> 00:13:32,940 You get China, India, America, Spain, and the different ones. 215 00:13:32,940 --> 00:13:33,320 Now, 216 00:13:33,320 --> 00:13:37,860 the nice thing here about using a CustomObject is that we 217 00:13:37,860 --> 00:13:40,700 are able to add things to the object. 218 00:13:40,700 --> 00:13:44,310 Now, I'm just going to copy a value here. 219 00:13:44,310 --> 00:13:46,530 So you can see the value. 220 00:13:46,530 --> 00:13:51,500 I've chosen that same variable, and this time I've piped it into Add‑Member, 221 00:13:51,500 --> 00:13:53,090 because I wish to add a member. 222 00:13:53,090 --> 00:13:59,340 And PSCustomObject has a NoteProperty, so I'm going to add this one to it. 223 00:13:59,340 --> 00:14:03,440 So if I go back to variable now, you'll see that Russia has now been added. 224 00:14:03,440 --> 00:14:08,040 If I go and just copy and paste another one here, 225 00:14:08,040 --> 00:14:10,250 there we go, we can see Norway. 226 00:14:10,250 --> 00:14:16,060 I can enter that, let me just clear the screen, and then do variable. 227 00:14:16,060 --> 00:14:19,030 You'll see we've now added to the original variable 228 00:14:19,030 --> 00:14:22,240 itself because it's a CustomObject. 229 00:14:22,240 --> 00:14:23,780 So that's the beauty of this. 230 00:14:23,780 --> 00:14:26,620 Now, what does that give us over everything else? 231 00:14:26,620 --> 00:14:31,540 Well, let's have a look at how we can retrieve values from this. 232 00:14:31,540 --> 00:14:36,440 Now notice I can just do variable.China and it gives me the value. 233 00:14:36,440 --> 00:14:41,440 I can do variable.Norway and I get those values back too. 234 00:14:41,440 --> 00:14:47,610 So it means I'm able to return the value from the CustomObject really simply. 235 00:14:47,610 --> 00:14:51,480 So, it's a nice way to store values, I suppose, 236 00:14:51,480 --> 00:14:55,740 almost in like an indexable way, where you're able to return the values. 237 00:14:55,740 --> 00:15:00,510 If I wanted to just get everything, then of course I could just do that, 238 00:15:00,510 --> 00:15:04,140 but of course if I tab through, I get the values, 239 00:15:04,140 --> 00:15:06,960 Spain, I get equals, I get all of the regular things, 240 00:15:06,960 --> 00:15:09,980 but all of those become properties on the object, 241 00:15:09,980 --> 00:15:17,000 so it's a nice way of being able to manage information that we need to populate and add in and reuse later.