1 00:00:00,510 --> 00:00:04,010 Hey guys, welcome to Day 20 of 100 2 00:00:04,010 --> 00:00:05,560 Days of Code. Today 3 00:00:05,680 --> 00:00:09,200 is really exciting because we're going to be using the knowledge that we've 4 00:00:09,200 --> 00:00:11,630 gained about Object Oriented Programming 5 00:00:11,990 --> 00:00:16,370 as well as what we learned about how to use the turtle module to build the 6 00:00:16,370 --> 00:00:18,830 famous snake game. Now, 7 00:00:18,830 --> 00:00:22,430 this is probably one of the most famous mobile games that ever was, 8 00:00:22,490 --> 00:00:27,490 and it's definitely one of my favorite. And my history with it goes back all the 9 00:00:28,760 --> 00:00:32,390 way to my very first mobile phone, 10 00:00:32,420 --> 00:00:37,280 the Nokia 3310. It might be showing my age a little bit here, 11 00:00:37,340 --> 00:00:40,580 but this was my first ever mobile phone. 12 00:00:40,890 --> 00:00:45,830 I remember loving it so much that I actually had it next to my pillow when I 13 00:00:45,830 --> 00:00:50,180 went to sleep. And this was probably one of the first affordable mobile phones. 14 00:00:50,270 --> 00:00:55,270 And it was endlessly customizable with different cases and different keys. 15 00:00:56,360 --> 00:00:58,640 But the most exciting thing about it 16 00:00:58,880 --> 00:01:01,090 was the snake game. I would compare 17 00:01:01,190 --> 00:01:04,489 with my friends and see who got the highest score in snake 18 00:01:04,730 --> 00:01:09,590 and we would spend days and days playing this game. And compared to the iPhone 19 00:01:09,590 --> 00:01:14,060 games of today, of course, this was very, very simple, but nonetheless, 20 00:01:14,060 --> 00:01:17,990 it is still super addictive. Over the next two days 21 00:01:18,110 --> 00:01:22,700 this is the game that we're going to build. A snake game that has, 22 00:01:22,760 --> 00:01:26,180 um, a moving snake, which you control using your keyboard, 23 00:01:26,630 --> 00:01:29,030 and you can go and get food, 24 00:01:29,300 --> 00:01:31,910 and then it grows in length as it eats more food. 25 00:01:32,240 --> 00:01:35,480 And you have to make sure that you don't end up getting tangled or hitting the 26 00:01:35,480 --> 00:01:36,170 wall. 27 00:01:36,170 --> 00:01:40,940 And the goal is to eat as much food as you can while staying alive. 28 00:01:41,600 --> 00:01:45,350 There are some people who are truly masters at this game, um, 29 00:01:45,410 --> 00:01:47,420 which I personally am not, 30 00:01:47,780 --> 00:01:52,430 but they managed to get their snakes to crazy lengths and start having these 31 00:01:52,430 --> 00:01:57,430 strategies for how you can avoid hitting your tail and how you can keep going. 32 00:01:58,100 --> 00:02:01,400 So once you've built your snake game, you'll be able to play with it, 33 00:02:01,550 --> 00:02:04,700 and you'll be able to show off your high scores to the rest of us, 34 00:02:04,910 --> 00:02:07,310 but I'm sure you're going to do a lot better than me. 35 00:02:07,700 --> 00:02:10,850 It's not that hard to beat me at snake. As always, 36 00:02:10,850 --> 00:02:13,040 when we're thinking about a complex problem 37 00:02:13,070 --> 00:02:16,340 the first step is to break down the problem. 38 00:02:16,940 --> 00:02:21,940 And I'm going to break down this problem of building the snake game into seven 39 00:02:22,040 --> 00:02:23,150 separate steps. 40 00:02:23,420 --> 00:02:26,660 And the way we're going to do it is we're going to tackle the first three steps 41 00:02:26,660 --> 00:02:30,470 on Day 1 and the last four steps on Day 2. 42 00:02:30,950 --> 00:02:34,730 So we're going to split up this game into two parts and we're going to tackle it 43 00:02:34,760 --> 00:02:39,680 over two days. The first step is to create a snake body, 44 00:02:40,070 --> 00:02:43,880 and we're going to do that by creating three squares on the screen, 45 00:02:44,270 --> 00:02:45,950 all lined up next to each other. 46 00:02:46,760 --> 00:02:51,290 And then we're going to figure out how to move the snake so that it continuously 47 00:02:51,290 --> 00:02:52,250 moves forward 48 00:02:52,460 --> 00:02:57,170 and all we have to do is tell it to change direction. Afterwards, 49 00:02:57,230 --> 00:03:01,300 we're going to figure out how to control the snake using keyboard controls. 50 00:03:01,570 --> 00:03:06,570 So we're going to be using the up, left, down, and right arrow keys to move our 51 00:03:07,240 --> 00:03:08,680 snake across the screen. 52 00:03:09,070 --> 00:03:12,520 And that is what we're aiming for by the end of today, 53 00:03:12,520 --> 00:03:14,920 Day 20. On Day 21, 54 00:03:15,070 --> 00:03:18,340 we're going to continue and we're going to build out the last four steps of the 55 00:03:18,340 --> 00:03:19,173 snake game. 56 00:03:19,630 --> 00:03:24,100 Then we'll need to start putting some food onto the screen and started to detect 57 00:03:24,100 --> 00:03:28,210 the collision with the food so that once the snake hits the food, 58 00:03:28,450 --> 00:03:33,400 then a new piece of food gets created randomly on the screen at some sort of 59 00:03:33,520 --> 00:03:34,570 random location. 60 00:03:35,410 --> 00:03:40,240 And then it's a matter of keeping track of the score and creating a scoreboard. 61 00:03:40,510 --> 00:03:45,430 So we're going to learn how to write text in our program so that once the snake 62 00:03:45,430 --> 00:03:48,970 hits a piece of food, the score automatically updates. 63 00:03:49,480 --> 00:03:52,870 And then next we're going to figure out when the game should end. 64 00:03:53,020 --> 00:03:58,020 So one of the cases when the game should end is when the snake has collided with 65 00:03:58,480 --> 00:04:02,470 the wall. And at this point we should see game over, 66 00:04:02,470 --> 00:04:06,430 show up on screen and the snake should no longer move. 67 00:04:06,910 --> 00:04:08,140 And then finally, 68 00:04:08,200 --> 00:04:12,880 the other reason why our game could end is when the snake has collided with its 69 00:04:12,880 --> 00:04:17,470 own tail. So the snake basically can't chase his own tail. 70 00:04:17,740 --> 00:04:21,610 And as the snake gets longer, this problem is more likely to occur. 71 00:04:22,060 --> 00:04:26,500 And when their head hits any part of the body of the snake, then it's again, 72 00:04:26,560 --> 00:04:29,860 game over. So these are the seven steps 73 00:04:29,890 --> 00:04:32,040 that it takes to create the snake game. 74 00:04:32,670 --> 00:04:37,440 And once you're ready, we're gonna get started with step one on the next lesson. 75 00:04:37,650 --> 00:04:38,340 So I'll see you there.