1 00:00:02,230 --> 00:00:05,270 So that's it for this section. 2 00:00:05,270 --> 00:00:06,650 It was a long section 3 00:00:06,650 --> 00:00:09,080 with a lot of code, which we changed. 4 00:00:09,080 --> 00:00:12,240 Now, we have this final result 5 00:00:12,240 --> 00:00:15,229 though I will already say one piece is missing. 6 00:00:15,229 --> 00:00:18,110 And that would be polymorphism, 7 00:00:18,110 --> 00:00:20,880 which also can help us with solving that problem 8 00:00:20,880 --> 00:00:24,160 of having duplicate if checks. 9 00:00:24,160 --> 00:00:25,560 We solved it for now 10 00:00:25,560 --> 00:00:28,879 by having this map full of functions, which works. 11 00:00:28,879 --> 00:00:31,740 But there is another approach using classes 12 00:00:31,740 --> 00:00:34,831 and polymorphism, which I will also come back to 13 00:00:34,831 --> 00:00:36,800 in the next section, however, 14 00:00:36,800 --> 00:00:39,410 because the next section will be about classes, 15 00:00:39,410 --> 00:00:42,580 objects and everything we need to know about them 16 00:00:42,580 --> 00:00:45,070 when it comes to writing clean code. 17 00:00:45,070 --> 00:00:46,490 So therefore, for the moment, 18 00:00:46,490 --> 00:00:48,760 this is the final state. 19 00:00:48,760 --> 00:00:50,180 And of course, you might argue 20 00:00:50,180 --> 00:00:52,810 that this is quite a long file 21 00:00:52,810 --> 00:00:57,080 with quite a lot of scrolling required to move around. 22 00:00:57,080 --> 00:00:59,562 Now, of course, keep a couple of things in mind. 23 00:00:59,562 --> 00:01:01,960 For one, we've got a bunch of dummy data here, 24 00:01:01,960 --> 00:01:05,420 which already occupies 30-ish lines of code. 25 00:01:05,420 --> 00:01:07,830 And then we get all these dummy methods down there 26 00:01:07,830 --> 00:01:09,360 at the bottom, which we, of course, 27 00:01:09,360 --> 00:01:11,230 also would have in reality 28 00:01:11,230 --> 00:01:12,950 with real code in there 29 00:01:12,950 --> 00:01:16,119 but they would probably not all be in the same file. 30 00:01:16,119 --> 00:01:19,547 And in general, this long file could be split up. 31 00:01:19,547 --> 00:01:23,030 I have an example folder structure here 32 00:01:23,030 --> 00:01:24,830 in the final-demo folder, 33 00:01:24,830 --> 00:01:26,646 which you also find attached. 34 00:01:26,646 --> 00:01:30,220 There, I have a very lean app.js file 35 00:01:30,220 --> 00:01:31,880 where we just have the main function, 36 00:01:31,880 --> 00:01:33,980 processTransactions and processTransaction 37 00:01:35,070 --> 00:01:36,800 and then all the other functions, 38 00:01:36,800 --> 00:01:38,270 which are being called in here 39 00:01:38,270 --> 00:01:41,240 are in the end imported from other files, 40 00:01:41,240 --> 00:01:43,190 which you find in subfolders. 41 00:01:43,190 --> 00:01:46,720 For example, the util folder has the error-handling function 42 00:01:46,720 --> 00:01:48,177 and my validator functions. 43 00:01:48,177 --> 00:01:51,931 The data folder simply holds these transactions 44 00:01:51,931 --> 00:01:53,566 and the processing folder 45 00:01:53,566 --> 00:01:57,180 has these functions that deal with the direct processing 46 00:01:57,180 --> 00:01:58,560 of the transactions. 47 00:01:58,560 --> 00:02:01,920 So the validation, and then also for processing 48 00:02:01,920 --> 00:02:04,843 with a processor, and picking a processor. 49 00:02:05,780 --> 00:02:07,210 And of course, in reality, 50 00:02:07,210 --> 00:02:09,350 you would split up code like this 51 00:02:09,350 --> 00:02:11,180 or in a similar way 52 00:02:11,180 --> 00:02:14,770 because that then makes the individual files easier to read 53 00:02:14,770 --> 00:02:18,560 and therefore, also helps with achieving clean code 54 00:02:18,560 --> 00:02:20,610 throughout your entire project. 55 00:02:20,610 --> 00:02:23,401 You don't just want to have one endless file. 56 00:02:23,401 --> 00:02:26,230 Of course, for the purpose of this section 57 00:02:26,230 --> 00:02:27,570 and for showing everything 58 00:02:27,570 --> 00:02:29,720 without switching files all the time, 59 00:02:29,720 --> 00:02:31,790 I did do it all in one file 60 00:02:31,790 --> 00:02:34,350 and even if you go through this file, therefore, 61 00:02:34,350 --> 00:02:36,640 it should still be rather clean. 62 00:02:36,640 --> 00:02:38,255 It reads top to bottom. 63 00:02:38,255 --> 00:02:41,130 We have these functions with good names, 64 00:02:41,130 --> 00:02:42,290 which we can call 65 00:02:42,290 --> 00:02:44,410 and we used all these functions 66 00:02:44,410 --> 00:02:46,350 and all these various concepts covered 67 00:02:46,350 --> 00:02:47,630 through this course 68 00:02:47,630 --> 00:02:50,350 to ensure that we still have a couple of if statements 69 00:02:50,350 --> 00:02:52,997 and a loop but we have less of them 70 00:02:52,997 --> 00:02:55,130 and we do combine them 71 00:02:55,130 --> 00:02:57,300 in a more structured way 72 00:02:57,300 --> 00:03:00,410 to ensure that we have way more readable code 73 00:03:00,410 --> 00:03:02,392 even though it takes up more lines of code 74 00:03:02,392 --> 00:03:05,030 than we had the beginning 75 00:03:05,030 --> 00:03:08,100 because this was definitely harder to read 76 00:03:08,100 --> 00:03:11,070 and understand and maintain and it had a lot 77 00:03:11,070 --> 00:03:13,160 of duplication inside of it. 78 00:03:13,160 --> 00:03:14,550 So now throughout this section, 79 00:03:14,550 --> 00:03:18,057 we learned how splitting this up into functions, 80 00:03:18,057 --> 00:03:20,930 something we already learned in the last section 81 00:03:20,930 --> 00:03:23,110 and how a couple of tweaks related 82 00:03:23,110 --> 00:03:24,920 to if statements 83 00:03:24,920 --> 00:03:27,381 and how to name our conditions and so on 84 00:03:27,381 --> 00:03:32,381 can help us with turning this into a way more readable 85 00:03:32,470 --> 00:03:34,970 and therefore cleaner code base.