WEBVTT 1 00:00:00.400 --> 00:00:03.520 Now that we know how to block on a single specific word. 2 00:00:03.520 --> 00:00:07.030 Let's expand our reach, and block more than just one offensive word. 3 00:00:07.030 --> 00:00:09.840 Now one trait that we have at our disposal, is that we can check 4 00:00:09.840 --> 00:00:14.640 multiple conditions by using what is known as a logical or expression. 5 00:00:14.640 --> 00:00:19.170 Which means we can do something like this, if the noun is dork, or 6 00:00:19.170 --> 00:00:22.230 the noun is jerk, exit the application. 7 00:00:22.230 --> 00:00:25.300 In fact you could chain these or statements on forever. 8 00:00:26.430 --> 00:00:28.500 Let's go introduce a logical OR 9 00:00:28.500 --> 00:00:32.700 into your application to block the user from entering either dork or jerk. 10 00:00:34.430 --> 00:00:37.580 Blocking against the word jerk in our code is actually pretty easy. 11 00:00:37.580 --> 00:00:41.580 In fact the only thing I think I need to show you is what OR syntax looks like. 12 00:00:41.580 --> 00:00:44.570 So let's go to our IF statement when we were checking for dork in the past. 13 00:00:45.800 --> 00:00:50.270 Let's add an OR statement in here, so we're gonna do a double pipe symbol. 14 00:00:50.270 --> 00:00:51.730 Pipe is above the enter key. 15 00:00:53.280 --> 00:00:58.189 That's what OR looks like so it's gonna say noun 16 00:00:58.189 --> 00:01:03.585 equals ignore case or noun equals lowercase on jerk. 17 00:01:05.587 --> 00:01:06.320 Great. 18 00:01:06.320 --> 00:01:10.230 Now this line is getting a little bit long and in fact if we added one more OR on 19 00:01:10.230 --> 00:01:13.310 here probably go off the screen and then somebody might not see that it's there. 20 00:01:13.310 --> 00:01:16.980 So one way that we can do to battle that is because we're inside of this 21 00:01:16.980 --> 00:01:18.490 parenthesis here. 22 00:01:18.490 --> 00:01:22.290 We can add a new line and take advantage of that space. 23 00:01:22.290 --> 00:01:24.200 So now looks much better. 24 00:01:25.280 --> 00:01:28.617 While we were writing that, one thing that you might have thought was that you could 25 00:01:28.617 --> 00:01:30.631 do the same thing with two if statements, right? 26 00:01:30.631 --> 00:01:35.101 You could write this if statement here you could say equalsIgnore "dork" or 27 00:01:35.101 --> 00:01:39.115 you can make another one that says if noun.equalsIgnore "jerk". 28 00:01:39.115 --> 00:01:42.154 But what would happen then is that you'd be writing these same lines inside of 29 00:01:42.154 --> 00:01:45.460 these, this code block here, you'd be writing that same code twice. 30 00:01:45.460 --> 00:01:47.734 And that's never a good idea. 31 00:01:47.734 --> 00:01:48.860 All right so let's give this a go. 32 00:01:48.860 --> 00:01:53.113 I'm gonna save it and then I'm gonna compile and run. 33 00:01:55.147 --> 00:01:56.345 I'll say 20. 34 00:01:58.019 --> 00:02:04.540 And we will do big and we're gonna put in jerk here, great, we caught it. 35 00:02:04.540 --> 00:02:06.190 So let's walk that really quick. 36 00:02:06.190 --> 00:02:09.962 So what we've done here is we have this first line that's gonna come in here. 37 00:02:09.962 --> 00:02:11.390 It's gonna say noun, and we put in, jerk. 38 00:02:11.390 --> 00:02:12.390 So noun is gonna be jerk. 39 00:02:12.390 --> 00:02:15.780 And it says, if noun equals dork, and that's a false. 40 00:02:15.780 --> 00:02:16.870 So that's going to say false. 41 00:02:16.870 --> 00:02:20.130 So, false or true. 42 00:02:20.130 --> 00:02:23.730 Right, because noun equals jerk and it does so we're going to say false or 43 00:02:23.730 --> 00:02:27.070 true and if you imagine that anytime there's a true in there. 44 00:02:27.070 --> 00:02:28.520 It's gonna be true. 45 00:02:28.520 --> 00:02:30.485 Okay, so let's make sure that the dork still works. 46 00:02:37.650 --> 00:02:39.640 Awesome it does after using this a bit, 47 00:02:39.640 --> 00:02:42.610 I think we need to do something different about that exit. 48 00:02:42.610 --> 00:02:46.130 It would be good to give the user a second chance to enter a nicer word. 49 00:02:46.130 --> 00:02:48.450 Let's see if we can't fix that in the next lesson. 50 00:02:48.450 --> 00:02:51.070 And one more thing I wanted to show if you wanted to do 51 00:02:51.070 --> 00:02:53.910 another one of these you can always chain them with another one. 52 00:02:53.910 --> 00:02:55.399 So right? So if we wanted to say. 53 00:02:57.731 --> 00:03:02.259 Another guy here, say nerd. 54 00:03:02.259 --> 00:03:07.100 All right perfect and that is how Ors work. 55 00:03:08.420 --> 00:03:12.570 Great we just learned one way that we could check multiple conditions in one 56 00:03:12.570 --> 00:03:13.090 IF statement. 57 00:03:14.140 --> 00:03:18.780 By not making two identical code blocks we avoided repeating ourselves. 58 00:03:18.780 --> 00:03:22.110 A goal of programming is to make sure that you don't repeat yourself or 59 00:03:22.110 --> 00:03:23.260 often referred to as DRY. 60 00:03:24.690 --> 00:03:28.410 As you advanced through your learnings, you'll hear this phrase often and I'm sure 61 00:03:28.410 --> 00:03:31.580 it will be hammered into your thinking as you begin coding bigger applications. 62 00:03:32.720 --> 00:03:34.230 What were you thinking about logic? 63 00:03:34.230 --> 00:03:37.540 I'd like to also introduce you to ORs counterpart which is AND. 64 00:03:38.650 --> 00:03:42.350 Well OR returns true if any statement is true and 65 00:03:42.350 --> 00:03:45.450 will only return true if all expressions are true. 66 00:03:46.480 --> 00:03:49.230 Logical and use the double ampersand simple 67 00:03:50.520 --> 00:03:54.370 as this logic is such an important concept and used all over the place. 68 00:03:54.370 --> 00:03:57.182 Let's go back and review our dating site analogy. 69 00:03:57.182 --> 00:04:01.080 So an example of an OR statement is must love cats or dogs. 70 00:04:01.080 --> 00:04:04.590 A cat lover would be tested and she'd say, do you love cats? 71 00:04:04.590 --> 00:04:07.430 And she'd say gee, yes, yes, yes, yes, yes. 72 00:04:07.430 --> 00:04:11.860 No need to ask about dogs as this person definitely met the requirement. 73 00:04:11.860 --> 00:04:13.830 Now let's look at another example. 74 00:04:13.830 --> 00:04:18.560 The request is younger than 40 and has no children and loves art. 75 00:04:18.560 --> 00:04:21.390 This elderly gentleman has prompted how old he is. 76 00:04:21.390 --> 00:04:25.330 And there is no need to go on asking any further questions as he doesn't meet 77 00:04:25.330 --> 00:04:26.950 all the conditions. 78 00:04:26.950 --> 00:04:27.730 Okay, so 79 00:04:27.730 --> 00:04:30.630 let's take a really quick exercise around the statements before we move on.