1 00:00:00,009 --> 00:00:03,299 We're going to take a break from replit and talk 2 00:00:03,309 --> 00:00:06,860 a little bit about algorithms because believe it or not, 3 00:00:07,159 --> 00:00:09,510 we're actually going to start working with 4 00:00:09,520 --> 00:00:13,739 slightly more advanced concepts in Python programming. 5 00:00:13,750 --> 00:00:16,379 And it's very, very important for you 6 00:00:16,850 --> 00:00:21,510 to understand what algorithms are because they are vital, 7 00:00:21,940 --> 00:00:25,950 not just for Python but any kind of programming language for that matter. 8 00:00:26,870 --> 00:00:31,459 Now, if I was to give you kind of like the standard definition of what an algorithm is, 9 00:00:31,469 --> 00:00:34,049 it's basically just like a set of instructions 10 00:00:34,439 --> 00:00:38,869 that need to be followed in order to arrive at a particular result. 11 00:00:39,029 --> 00:00:39,490 OK. 12 00:00:40,380 --> 00:00:44,919 In this case, right now, you can see this text, I have written some stuff there. 13 00:00:45,659 --> 00:00:48,880 The very first statement says if 14 00:00:49,159 --> 00:00:52,069 the computer is running fast, 15 00:00:53,290 --> 00:00:53,979 finish. 16 00:00:54,880 --> 00:00:56,139 Now, what do I mean here? 17 00:00:56,150 --> 00:01:00,340 I'm simply saying that look, if our computer is performing very, very well, 18 00:01:00,349 --> 00:01:01,819 it's running very, very quickly. 19 00:01:02,360 --> 00:01:07,540 There is no need to check for anything, it's fine, right? That's why I said finish. 20 00:01:08,339 --> 00:01:11,519 But then notice on the third line, I said 21 00:01:12,959 --> 00:01:15,739 you could also say something like but 22 00:01:15,959 --> 00:01:17,860 right? But in programming language 23 00:01:18,269 --> 00:01:20,680 we don't use but we use, 24 00:01:20,860 --> 00:01:21,489 all right. 25 00:01:21,790 --> 00:01:22,120 So 26 00:01:22,529 --> 00:01:28,980 basically is signifying that if the previous statement is not correct. 27 00:01:29,650 --> 00:01:33,269 So if the computer isn't running fast, 28 00:01:34,169 --> 00:01:36,879 ok, then what do we now need to do? 29 00:01:38,080 --> 00:01:40,529 We need to, first of all check if there is a virus 30 00:01:41,430 --> 00:01:46,389 and then after that, we might need to uninstall unnecessary programs 31 00:01:47,069 --> 00:01:50,519 and then we might eventually need to increase the ramp. 32 00:01:50,529 --> 00:01:52,900 So if we follow these three steps, a 33 00:01:53,300 --> 00:01:54,449 computer 34 00:01:54,779 --> 00:01:58,290 will be guaranteed to run faster. 35 00:01:59,150 --> 00:02:03,720 This is a go with him, right? And two keywords here are the if 36 00:02:04,059 --> 00:02:05,529 and else 37 00:02:05,650 --> 00:02:09,179 we're going to be working with this quite a lot in 38 00:02:09,470 --> 00:02:10,630 this course. 39 00:02:10,880 --> 00:02:14,320 And if you are ever going to work with a different kind of programming language, 40 00:02:14,589 --> 00:02:17,770 you will always come across if else, statements, 41 00:02:17,779 --> 00:02:21,770 these are fundamental building blocks of any program. 42 00:02:22,750 --> 00:02:25,130 I hope you understand what we did here 43 00:02:25,410 --> 00:02:26,410 pretty straightforward. 44 00:02:27,179 --> 00:02:27,830 I'm gonna 45 00:02:28,080 --> 00:02:32,360 make this just a little bit more advanced. Ok. Just a little bit. All right. 46 00:02:33,070 --> 00:02:34,139 Let me open up the 47 00:02:34,339 --> 00:02:35,130 second tab. 48 00:02:36,089 --> 00:02:36,589 So 49 00:02:37,429 --> 00:02:41,639 imagine you're getting dressed based on the weather. 50 00:02:42,070 --> 00:02:42,889 Ok. So 51 00:02:43,199 --> 00:02:46,610 the very first statement we've established a scenario, right? 52 00:02:47,279 --> 00:02:49,619 So our program is checking to see 53 00:02:49,940 --> 00:02:54,139 what we should wear based on the weather. 54 00:02:54,559 --> 00:02:55,179 So 55 00:02:55,300 --> 00:02:56,979 we have the very first result 56 00:02:58,029 --> 00:03:00,410 if the weather is sunny. 57 00:03:00,559 --> 00:03:03,839 Ok. Well, we can wear our sunglasses. 58 00:03:05,600 --> 00:03:06,259 However, 59 00:03:07,389 --> 00:03:11,669 notice the third line it goes else if 60 00:03:12,889 --> 00:03:15,850 it's no longer just else, 61 00:03:16,009 --> 00:03:16,630 why? 62 00:03:17,729 --> 00:03:22,440 Well, because the weather can come in various forms, 63 00:03:22,610 --> 00:03:27,149 it could be sunny, it could be rainy, it could be snowing, it could be cloudy. 64 00:03:27,449 --> 00:03:32,160 There's a lot more options. Right. In the very first document here, 65 00:03:32,300 --> 00:03:36,149 there are only two conditions. The first condition is, is the computer running fast 66 00:03:36,279 --> 00:03:38,220 or is it not running fast? 67 00:03:38,330 --> 00:03:38,910 That's it. 68 00:03:39,199 --> 00:03:40,100 Nothing 69 00:03:40,320 --> 00:03:45,839 like. Is the computer running at 25% capacity? Is it running at 50% capacity? 70 00:03:45,899 --> 00:03:48,149 We don't have any other conditions. It's just to 71 00:03:48,289 --> 00:03:51,919 either the company is running fast or it isn't. It's either A or B 72 00:03:52,020 --> 00:03:55,339 that's why if else would work perfectly here. 73 00:03:55,350 --> 00:03:59,899 However, in this example, we have more than two options 74 00:04:00,679 --> 00:04:02,539 because again, we're dealing with the weather. 75 00:04:03,339 --> 00:04:03,800 So 76 00:04:04,770 --> 00:04:05,710 if it's sunny, 77 00:04:06,410 --> 00:04:08,100 we can wear our sunglasses. 78 00:04:08,860 --> 00:04:12,169 Else if it's raining, 79 00:04:12,600 --> 00:04:14,399 ok, we can take an umbrella 80 00:04:15,470 --> 00:04:18,829 and then else if it's snowing, 81 00:04:19,309 --> 00:04:22,089 we can put on a heavy coat, 82 00:04:22,459 --> 00:04:23,010 right? 83 00:04:23,839 --> 00:04:27,700 But now look at the very last line, it simply says else, 84 00:04:28,209 --> 00:04:30,220 not else if else 85 00:04:30,890 --> 00:04:33,750 because basically we are concluding 86 00:04:33,970 --> 00:04:34,950 the program here. 87 00:04:34,959 --> 00:04:38,829 We're saying, ok, we've checked, if it's sunny, we've checked, if it's raining, 88 00:04:38,839 --> 00:04:40,359 we've checked if it's snowing. 89 00:04:40,609 --> 00:04:44,549 So if it's none of these three 90 00:04:45,609 --> 00:04:49,100 is going to be just a normal day, so else 91 00:04:49,220 --> 00:04:50,390 just dress normally. 92 00:04:51,950 --> 00:04:52,529 Ok. 93 00:04:53,290 --> 00:04:53,790 So 94 00:04:54,299 --> 00:04:57,959 the very first one here again is simply if else because there are two conditions. 95 00:04:58,250 --> 00:05:01,500 The second one here, we do have the else if statement because 96 00:05:01,670 --> 00:05:04,059 there is more than two conditions. 97 00:05:04,070 --> 00:05:08,350 In fact, there are four different results based on the weather. 98 00:05:08,630 --> 00:05:11,820 That's why we can no longer just work with the if else we have to introduce the 99 00:05:12,600 --> 00:05:14,570 if statement. 100 00:05:14,809 --> 00:05:17,470 So hopefully, you understand 101 00:05:17,970 --> 00:05:23,429 why we use the if else statement in here and why we used else if in here, 102 00:05:23,649 --> 00:05:28,709 if you don't, maybe hopefully once we begin to create actual programs 103 00:05:28,929 --> 00:05:31,959 using the algorithms, you will understand it much better then. 104 00:05:32,299 --> 00:05:37,380 But this has been an introduction to the world of algorithms as well as the if else, 105 00:05:37,390 --> 00:05:38,160 if statements. 106 00:05:38,170 --> 00:05:40,440 Thank you for watching. I will see you in the next class.