WEBVTT 0 00:00.030 --> 00:04.500 Hey! Welcome to Day 16 of 100 Days of Code. Now 1 00:04.530 --> 00:05.100 today, 2 00:05.100 --> 00:08.250 we're going to be pulling out the big guns, we're going to be learning about 3 00:08.280 --> 00:12.210 Object Oriented Programming otherwise known as OOP. 4 00:12.630 --> 00:16.890 Why are we learning about it? Well, if you think back to yesterday's project, 5 00:17.310 --> 00:21.450 some of you I'm sure at some point during the project, would have had this 6 00:21.450 --> 00:25.740 feeling of what on earth is going on with my code? 7 00:25.920 --> 00:30.060 And the reason is because our code is getting more complex, 8 00:30.330 --> 00:32.370 it's trying to do a lot of things, 9 00:32.490 --> 00:35.850 and it's trying to manage a whole bunch of relationships. 10 00:36.150 --> 00:39.540 So one function is changing a variable, 11 00:39.540 --> 00:43.740 and then that same function is doing something else to another variable. 12 00:44.100 --> 00:48.810 And at some point, the logic of our code starts looking very, very spaghetti- 13 00:48.810 --> 00:49.643 like. 14 00:49.920 --> 00:54.630 And it's at this point where it's really hard to track and remember what's 15 00:54.720 --> 00:56.460 actually going on in our code. 16 00:57.180 --> 01:00.510 So this style of programming is called Procedural 17 01:00.510 --> 01:05.510 Programming where we set up procedures or functions that do particular things. 18 01:06.600 --> 01:11.250 And then one procedure leads to another procedure, and all in all, the computer's 19 01:11.250 --> 01:15.690 mostly working from top to bottom and then jumping out into a function as 20 01:15.690 --> 01:16.523 needed. 21 01:17.250 --> 01:22.110 Procedural programming is one of the earliest paradigms of Programming. 22 01:22.410 --> 01:27.210 In fact, back in the days when we had older languages like Fortran and COBOL, 23 01:27.840 --> 01:30.840 they rely pretty much exclusively on procedural 24 01:30.840 --> 01:32.670 programming like what we've been doing. 25 01:33.780 --> 01:36.120 But the increase in complexity, 26 01:36.150 --> 01:40.410 the increase in the number of relationships that we need to remember and manage 27 01:40.800 --> 01:45.540 starts making it look a bit like the dating history of the Kardashians. 28 01:45.930 --> 01:47.160 And it gets very, 29 01:47.160 --> 01:52.020 very confusing because everybody has been in touch with somebody else. Now, 30 01:52.080 --> 01:56.280 the kind of relationships I prefer are one to one, me and my couch. 31 01:56.700 --> 02:01.700 So how can we maintain a simple relationship in our code while being able to 32 02:03.120 --> 02:07.320 write more and more complex projects? Well, 33 02:07.350 --> 02:11.430 this is where the Object-Oriented paradigm comes in really handy. 34 02:12.090 --> 02:17.090 Now let's imagine that you're tasked with creating the program for a self- 35 02:18.150 --> 02:21.090 driving car. Now, as you can imagine, 36 02:21.090 --> 02:24.660 this is a pretty complex project and it's many, 37 02:24.660 --> 02:29.220 many notches above the coffee machine that we've been struggling with so far. 38 02:29.970 --> 02:33.630 But what if you broke it down? What is a self-driving car? 39 02:34.020 --> 02:38.160 What are the different components that make up a self-driving car? Well, 40 02:38.220 --> 02:43.220 it probably needs some sort of camera module to keep track of what's on the road 41 02:43.560 --> 02:45.360 and to recognize what's on the road, 42 02:45.990 --> 02:50.990 it will probably need a form of lane detection to know if we're actually within 43 02:51.750 --> 02:56.750 the lane or if we need to turn off or if we need to park, and it will need some 44 02:58.560 --> 03:02.740 way of navigating so that when the user says, I want to go to the bank, 45 03:02.980 --> 03:05.290 they identify the branch they want to go to, 46 03:05.380 --> 03:09.370 and then the navigation gets set up and the car knows how to get there. 47 03:09.940 --> 03:14.080 And finally, you'll probably need some form of fuel management, right? 48 03:14.140 --> 03:16.330 What should happen when the fuel gets low? 49 03:16.660 --> 03:20.290 Should it go and automatically recharge at a specified point? 50 03:20.800 --> 03:24.010 Now I'm obviously simplifying this task. There's a lot, 51 03:24.010 --> 03:27.160 a lot more that goes into making an automated car. 52 03:27.730 --> 03:32.140 But we've already managed to break it down into several modules that we can 53 03:32.320 --> 03:34.000 think about tackling, right? 54 03:34.540 --> 03:39.540 But imagine if you have a whole team who are all working on this project and 55 03:39.790 --> 03:40.750 within that team, 56 03:40.750 --> 03:45.010 there's sub-teams who are working on each of these different modules. 57 03:45.490 --> 03:50.490 Well then by splitting up this big complex task into separate modules, 58 03:51.520 --> 03:54.640 then we can all work on this car simultaneously, 59 03:55.570 --> 03:57.820 massively improving our productivity, 60 03:58.180 --> 04:02.500 making it much quicker to eventually build all the software for this car. 61 04:03.280 --> 04:06.850 Plus on top of that, a lot of these modules are reusable. 62 04:07.270 --> 04:12.270 So if it just so happens that the next year we're tasked with building a drone, 63 04:12.640 --> 04:16.390 well, a lot of those programming modules that we built, like the camera module, 64 04:16.390 --> 04:18.700 the fuel management, the navigation, 65 04:18.910 --> 04:23.910 that's all going to be incredibly useful in our drone delivery software as well. 66 04:24.370 --> 04:29.370 And because we've taken out these individual chunks of code and modularized them 67 04:29.890 --> 04:32.020 using Object Oriented Programming, 68 04:32.260 --> 04:36.340 we won't have to code them up again in the same way that we might need to 69 04:36.460 --> 04:38.380 if we were using procedural programming. 70 04:39.180 --> 04:44.180 So what exactly is all Object Oriented Programming? We've seen that we can split 71 04:46.140 --> 04:49.620 a larger task into that smaller pieces. 72 04:50.070 --> 04:54.690 And each of those pieces can be worked on by separate teams, separate people, 73 04:54.990 --> 04:59.460 and also each of those pieces become reusable if we need the same 74 04:59.460 --> 05:03.030 functionality in the future. But Object Oriented 75 05:03.030 --> 05:05.940 Programming actually takes that concept even further. 76 05:06.510 --> 05:08.130 And I think the best way to explain it 77 05:08.340 --> 05:11.730 is to imagine that you are tasked with running a restaurant. 78 05:12.420 --> 05:16.320 So you take over this restaurant from your long lost uncle 79 05:16.440 --> 05:19.980 and you realize that it's actually really hard running a restaurant. 80 05:20.550 --> 05:25.550 So, first off, you have to be the receptionist and you reserve seats for your 81 05:26.220 --> 05:29.400 restaurant visitor's and then when they order something, 82 05:29.430 --> 05:32.520 you have to be the waitress and bring them their order. 83 05:32.970 --> 05:35.370 And then of course the order needs to be cooked up, right? 84 05:35.370 --> 05:39.600 So you're also gonna run into the kitchen and be the chef, create the thing that 85 05:39.600 --> 05:41.130 they ordered and finally, 86 05:41.130 --> 05:44.550 you're also going to be the cleaner tidying up after everybody 87 05:44.580 --> 05:47.070 once they've left. As you can imagine, 88 05:47.070 --> 05:50.280 if you were one person having to do all of these tasks, 89 05:50.730 --> 05:55.410 that's going to be a pretty rough day. There are in fact one-man restaurants, 90 05:55.500 --> 05:58.310 and I've seen some work really in well Japan, 91 05:58.700 --> 06:01.970 where you have one person who's taking the order, 92 06:02.300 --> 06:05.300 who's making the food, who's tidying up after you. 93 06:05.720 --> 06:10.040 But the limitation here though, is that look at how many seats he has. 94 06:10.190 --> 06:15.190 You can't have a large restaurant running everything by yourself. In the same 95 06:16.340 --> 06:20.780 way we can't create a very complex and really large software project 96 06:21.170 --> 06:25.370 if we are using a procedural style of programming where we're sort of running a 97 06:25.370 --> 06:27.380 one man band. It gets very, 98 06:27.380 --> 06:30.620 very complex and very hard to manage very quickly. 99 06:31.280 --> 06:33.260 So lets consider the alternative. 100 06:33.770 --> 06:38.770 What if we had just hired a bunch of people where they each have their own 101 06:39.290 --> 06:42.590 individual roles. They're trained for it, they know what to do. 102 06:42.800 --> 06:46.940 The waiter knows how to wait and the chef knows how to cook. Well, 103 06:46.940 --> 06:47.600 in this case, 104 06:47.600 --> 06:52.600 you could just be the manager and you can manage all of your staff and tell them 105 06:53.210 --> 06:54.560 what it is that they need to do. 106 06:54.980 --> 06:59.510 But then you won't have to worry about the nitty-gritty details of exactly how 107 06:59.510 --> 07:02.660 they need to go about doing their jobs. So for example, 108 07:02.660 --> 07:04.040 you don't need to tell the waiter 109 07:04.050 --> 07:08.300 how to wait on customers and you don't need to tell the chef how to cook an egg 110 07:08.450 --> 07:10.370 because they already know how to do that. 111 07:11.000 --> 07:16.000 And we can use the same concept to simplify the relationships in our code and 112 07:17.090 --> 07:21.080 make it scalable for a larger and more complex project.