1 00:00:00,180 --> 00:00:01,080 Welcome back. 2 00:00:01,080 --> 00:00:06,720 So now we're going to discuss what are called boolean expressions. 3 00:00:06,720 --> 00:00:12,730 And we can go ahead and just type this right into our text file if you don't have your file open with 4 00:00:12,760 --> 00:00:13,170 GZA. 5 00:00:13,170 --> 00:00:21,030 Go ahead and get your script up high open and we're gonna do is we're going to just put in here boolean 6 00:00:21,060 --> 00:00:21,970 expressions. 7 00:00:22,650 --> 00:00:29,370 And now when we say boolean expressions we can just think of this as true or false. 8 00:00:30,690 --> 00:00:38,010 So let's go ahead and print our new subject line or to in a call these boolean expressions. 9 00:00:38,970 --> 00:00:47,080 And from here let's start defining those so let's say we have boolean expression one we'll just call 10 00:00:47,080 --> 00:00:49,620 the variable bool one. 11 00:00:49,620 --> 00:00:52,480 Now let's just set that equal to true. 12 00:00:53,590 --> 00:00:54,030 OK. 13 00:00:54,730 --> 00:00:57,280 And let's give an example of that as well. 14 00:00:57,280 --> 00:01:05,930 Let's just say boolean to equals let's say three times three now. 15 00:01:05,960 --> 00:01:07,730 What does three times three equals. 16 00:01:07,730 --> 00:01:08,840 Well that equals nine. 17 00:01:09,140 --> 00:01:14,270 So we can say equals equals to mean something equals something. 18 00:01:14,270 --> 00:01:16,790 And so this number equals this number. 19 00:01:16,790 --> 00:01:19,360 So three times three is nine which equals nine. 20 00:01:19,370 --> 00:01:28,670 So if we take this expression and we say nine equals nine it's going to return true. 21 00:01:28,670 --> 00:01:29,690 Let's do a couple more. 22 00:01:29,750 --> 00:01:39,570 So we could say a billion three equals false and billion four equals three times three. 23 00:01:39,570 --> 00:01:43,500 And then we can say does not equal nine. 24 00:01:44,370 --> 00:01:45,500 Well that's not true. 25 00:01:45,510 --> 00:01:45,870 Right. 26 00:01:45,900 --> 00:01:47,730 So that's false. 27 00:01:47,760 --> 00:01:59,970 So if we were to print these all out we could say print billion one billion to both three and bull for. 28 00:02:00,190 --> 00:02:00,850 OK. 29 00:02:00,850 --> 00:02:02,620 And let's also print the type. 30 00:02:02,650 --> 00:02:04,070 So we know about this. 31 00:02:04,490 --> 00:02:05,730 So there's a print type. 32 00:02:05,950 --> 00:02:13,370 And let's take a look at what this looks like so once you have that all written out go ahead and just 33 00:02:13,370 --> 00:02:23,910 save this and go ahead and run your file and you can see that it came out exactly how we thought it 34 00:02:23,910 --> 00:02:25,410 would. 35 00:02:25,410 --> 00:02:30,390 So we've got four variables and they're all boolean expressions right. 36 00:02:30,420 --> 00:02:34,140 So we've got true this equals to true. 37 00:02:34,140 --> 00:02:35,370 This is false. 38 00:02:35,730 --> 00:02:38,240 And this is equal to False. 39 00:02:38,310 --> 00:02:40,380 So we see a true true false false. 40 00:02:40,380 --> 00:02:46,290 We print those all out and then when we want to look at the type of the variable so we say hey what's 41 00:02:46,290 --> 00:02:50,640 stored in here inside this variable what's stored is a boolean. 42 00:02:50,640 --> 00:02:57,180 Now please do note that there is a difference between true and true. 43 00:02:57,180 --> 00:02:59,400 One is a string and one is a boolean. 44 00:02:59,760 --> 00:03:10,320 So if you were to set boolean Phi for example to true and then you printed the type of boolean five 45 00:03:11,310 --> 00:03:15,280 then you're going to get a different result here. 46 00:03:15,660 --> 00:03:19,860 You're going to see now that the type is a class of string. 47 00:03:19,860 --> 00:03:24,330 So big difference here I'm going to go ahead and just delete this. 48 00:03:24,360 --> 00:03:28,980 So this is just an overview of boolean expressions. 49 00:03:28,980 --> 00:03:35,730 We're going to use this later on and you will see it again when we get into X flight development. 50 00:03:36,120 --> 00:03:40,860 But you're going to see certain things especially when you get into loops as well. 51 00:03:40,860 --> 00:03:46,270 So once we start getting into looping and we talk about that it will make a little bit more sense. 52 00:03:46,410 --> 00:03:53,640 But you want to know sometimes if something is true or something is false or when we get into conditional 53 00:03:53,640 --> 00:03:59,520 statements if something is true then do this or if something is false do this. 54 00:03:59,520 --> 00:04:03,990 We haven't gotten quite that far yet but we need to introduce the concepts before we can build upon 55 00:04:03,990 --> 00:04:04,170 it. 56 00:04:04,620 --> 00:04:09,150 So we're gonna do in the next video is we're going to build upon these even more. 57 00:04:09,240 --> 00:04:15,780 We're going to take relational operators and these boolean expressions and kind of combine them and 58 00:04:15,780 --> 00:04:16,820 start building upon it. 59 00:04:16,830 --> 00:04:20,430 And then once we get this all put together it'll all start making sense. 60 00:04:20,460 --> 00:04:26,130 So for now all you need to know is when I say bullying expression all I'm thinking about is true or 61 00:04:26,130 --> 00:04:26,700 false. 62 00:04:26,910 --> 00:04:29,040 So we'll build upon that in later videos.