1 00:00:01,540 --> 00:00:03,040 ‫Welcome back. 2 00:00:03,040 --> 00:00:06,120 ‫So I hope that you have Node installed 3 00:00:06,120 --> 00:00:08,100 ‫on your computer at this point. 4 00:00:08,100 --> 00:00:09,830 ‫And so, let's now actually go ahead 5 00:00:09,830 --> 00:00:12,793 ‫and use Node for the very first time. 6 00:00:14,530 --> 00:00:16,760 ‫And to get started with the section, 7 00:00:16,760 --> 00:00:19,760 ‫please go into the course starter files 8 00:00:19,760 --> 00:00:24,300 ‫and copy this folder to your working directory, okay? 9 00:00:24,300 --> 00:00:27,120 ‫Now, if you didn't download the course files yet, 10 00:00:27,120 --> 00:00:29,360 ‫please go to the GitHub repository, 11 00:00:29,360 --> 00:00:31,670 ‫that is linked all over the course, 12 00:00:31,670 --> 00:00:35,390 ‫and you will find all the files that you need in there. 13 00:00:35,390 --> 00:00:37,290 ‫Then after that, go ahead and open up 14 00:00:37,290 --> 00:00:39,770 ‫the folder in your code editor. 15 00:00:39,770 --> 00:00:42,070 ‫And I'm using VS Code here. 16 00:00:42,070 --> 00:00:45,400 ‫And I actually already loaded it up. 17 00:00:45,400 --> 00:00:49,310 ‫So here is this Node Farm folder. 18 00:00:49,310 --> 00:00:51,290 ‫Now in this video, we will actually 19 00:00:51,290 --> 00:00:53,500 ‫not yet start with the project. 20 00:00:53,500 --> 00:00:55,760 ‫But instead, we're gonna interact with Node 21 00:00:55,760 --> 00:00:58,010 ‫using the command line. 22 00:00:58,010 --> 00:01:00,530 ‫And for that, I'm gonna use the built-in terminal 23 00:01:00,530 --> 00:01:04,270 ‫that VS Code has, hitting control back take for that. 24 00:01:04,270 --> 00:01:07,090 ‫So this command that you see here, actually. 25 00:01:07,090 --> 00:01:11,180 ‫Or you can go to View and Terminal. 26 00:01:11,180 --> 00:01:13,540 ‫Now if you prefer to use another application 27 00:01:13,540 --> 00:01:15,720 ‫for the terminal, that's fine as well 28 00:01:15,720 --> 00:01:17,330 ‫but throughout this course, 29 00:01:17,330 --> 00:01:19,150 ‫I'm always going to use the terminal 30 00:01:19,150 --> 00:01:21,330 ‫that is built in right into VS Code 31 00:01:21,330 --> 00:01:23,600 ‫so that we don't have to jump around 32 00:01:23,600 --> 00:01:26,040 ‫between different windows so much. 33 00:01:26,040 --> 00:01:29,640 ‫Now, to start writing some Node code here in the console, 34 00:01:29,640 --> 00:01:31,753 ‫all we have to do is to write node, 35 00:01:32,790 --> 00:01:36,150 ‫given that you have Node.js installed on your computer 36 00:01:36,150 --> 00:01:38,490 ‫and then, just hit enter. 37 00:01:38,490 --> 00:01:41,320 ‫And this will then open up the Node REPL, 38 00:01:41,320 --> 00:01:45,080 ‫which stands for read-eval-print loop. 39 00:01:45,080 --> 00:01:47,910 ‫So basically here, we can write JavaScript code 40 00:01:47,910 --> 00:01:50,390 ‫just like in a normal terminal. 41 00:01:50,390 --> 00:01:52,363 ‫For example, we can define variables. 42 00:01:56,250 --> 00:01:58,830 ‫And so, here it is. 43 00:01:58,830 --> 00:02:01,760 ‫So, we just defined the name variable. 44 00:02:01,760 --> 00:02:04,030 ‫And in fact, we can write any JavaScript code 45 00:02:04,030 --> 00:02:06,590 ‫that we like in here, okay? 46 00:02:06,590 --> 00:02:08,890 ‫So, that's because at the end of the day, 47 00:02:08,890 --> 00:02:12,080 ‫Node.js is really just a JavaScript run time, 48 00:02:12,080 --> 00:02:14,210 ‫as we just saw before. 49 00:02:14,210 --> 00:02:15,780 ‫So what else can we do? 50 00:02:15,780 --> 00:02:19,100 ‫Well, any type of expression really, will work. 51 00:02:19,100 --> 00:02:22,680 ‫Let's just do some math here, for example. 52 00:02:22,680 --> 00:02:24,730 ‫Okay so any JavaScript will work 53 00:02:24,730 --> 00:02:26,760 ‫and you see that we actually 54 00:02:26,760 --> 00:02:31,040 ‫defined this variable here using const so that is ES6 55 00:02:31,040 --> 00:02:34,750 ‫and that is absolutely no problem in Node.js. 56 00:02:34,750 --> 00:02:38,100 ‫So it supports ES6 in all the newer versions 57 00:02:38,100 --> 00:02:40,800 ‫out of the box without any problem. 58 00:02:40,800 --> 00:02:42,250 ‫That's because we're not running 59 00:02:42,250 --> 00:02:44,850 ‫this JavaScript in any browser, 60 00:02:44,850 --> 00:02:48,380 ‫but it will always run on the server, okay? 61 00:02:48,380 --> 00:02:52,400 ‫So, in fact, we just took JavaScript out of the browser 62 00:02:52,400 --> 00:02:56,350 ‫and we're running it inside of this Node application. 63 00:02:56,350 --> 00:02:59,470 ‫Now if we wanted to exit JS REPL, 64 00:02:59,470 --> 00:03:03,750 ‫so again, this read-eval-print loop, that Node gives us, 65 00:03:03,750 --> 00:03:06,210 ‫there are different ways of doing that. 66 00:03:06,210 --> 00:03:08,310 ‫The first one is to write exit 67 00:03:08,310 --> 00:03:09,660 ‫or actually .exit 68 00:03:11,420 --> 00:03:16,060 ‫and so this exited this Node process, this REPL 69 00:03:16,060 --> 00:03:18,300 ‫and so that started again so that I can 70 00:03:18,300 --> 00:03:20,050 ‫show you some more stuff. 71 00:03:20,050 --> 00:03:25,050 ‫So again, just type Node, hit enter, and that's it. 72 00:03:25,260 --> 00:03:27,000 ‫Oh, and, by the way, if you want to 73 00:03:27,000 --> 00:03:29,160 ‫clear your terminal like I just did, 74 00:03:29,160 --> 00:03:31,910 ‫all you have to do is to hit command K 75 00:03:31,910 --> 00:03:34,890 ‫and that will then clear the command line 76 00:03:34,890 --> 00:03:39,160 ‫and probably on Windows, that is control K, okay? 77 00:03:39,160 --> 00:03:43,890 ‫Anyway, we use the .exit to exit the REPL 78 00:03:43,890 --> 00:03:47,030 ‫but we can also hit control D, 79 00:03:47,030 --> 00:03:49,980 ‫and that's not command, it is really control, 80 00:03:49,980 --> 00:03:53,600 ‫so control D will do the same. 81 00:03:53,600 --> 00:03:55,610 ‫But, let's quickly enter it again 82 00:03:55,610 --> 00:03:58,830 ‫'cause there's some more stuff that I want to show you. 83 00:03:58,830 --> 00:04:00,960 ‫So if you hit tab right now, 84 00:04:00,960 --> 00:04:02,870 ‫maybe you have to tap it twice, 85 00:04:02,870 --> 00:04:05,590 ‫sometimes that happens for some reason, 86 00:04:05,590 --> 00:04:07,880 ‫but anyway, by hitting tab, 87 00:04:07,880 --> 00:04:10,220 ‫you can see all the global variables 88 00:04:10,220 --> 00:04:12,720 ‫that are available in Node. 89 00:04:12,720 --> 00:04:14,100 ‫So you have all the kind of stuff 90 00:04:14,100 --> 00:04:15,370 ‫that we're already used to 91 00:04:15,370 --> 00:04:17,670 ‫like the Array constructor 92 00:04:17,670 --> 00:04:19,830 ‫or the String constructor 93 00:04:19,830 --> 00:04:21,290 ‫or Math 94 00:04:21,290 --> 00:04:23,900 ‫or Number over here, 95 00:04:23,900 --> 00:04:25,950 ‫but then there's also all kinds of stuff 96 00:04:25,950 --> 00:04:27,670 ‫that belongs to Node. 97 00:04:27,670 --> 00:04:31,840 ‫For example, your https and fs or crypto 98 00:04:31,840 --> 00:04:33,950 ‫and these are Node modules 99 00:04:33,950 --> 00:04:35,710 ‫that we're gonna talk more about 100 00:04:35,710 --> 00:04:37,880 ‫a bit later in the section. 101 00:04:37,880 --> 00:04:40,650 ‫But for now, you see that we have all kinds 102 00:04:40,650 --> 00:04:43,120 ‫of global variables that we can access 103 00:04:43,120 --> 00:04:47,320 ‫whenever we want in Node.js, okay? 104 00:04:47,320 --> 00:04:51,000 ‫Also, another nice trick is the underscore variable. 105 00:04:51,000 --> 00:04:53,440 ‫So let me first show you something. 106 00:04:53,440 --> 00:04:55,270 ‫So another calculation for example. 107 00:04:55,270 --> 00:04:59,220 ‫Three times eight gives 24 108 00:04:59,220 --> 00:05:03,710 ‫and now was can use underscore plus six 109 00:05:03,710 --> 00:05:07,180 ‫and so this will give us 30 110 00:05:07,180 --> 00:05:09,610 ‫and so that means that underscore 111 00:05:09,610 --> 00:05:12,330 ‫is basically your previous result. 112 00:05:12,330 --> 00:05:16,110 ‫So we had 24, and so underscore here is 24 now 113 00:05:16,110 --> 00:05:19,330 ‫and 24 plus six makes 30. 114 00:05:19,330 --> 00:05:22,130 ‫So if we now did underscore minus 30, 115 00:05:22,130 --> 00:05:24,410 ‫that will give us zero, right? 116 00:05:24,410 --> 00:05:26,390 ‫And yeah, it did. 117 00:05:26,390 --> 00:05:31,390 ‫Okay, and finally, the tab that you just pressed before, 118 00:05:31,460 --> 00:05:34,440 ‫you can also press that, for example, 119 00:05:34,440 --> 00:05:36,010 ‫on one of these constructor 120 00:05:36,010 --> 00:05:37,930 ‫that we already know like string. 121 00:05:37,930 --> 00:05:41,240 ‫So String. and now by adding tab, 122 00:05:41,240 --> 00:05:43,420 ‫you can see all the methods or properties 123 00:05:43,420 --> 00:05:45,350 ‫that are available to us. 124 00:05:45,350 --> 00:05:47,860 ‫Again, sometimes you have to hit it twice 125 00:05:47,860 --> 00:05:49,400 ‫but then here we are. 126 00:05:49,400 --> 00:05:53,140 ‫So we have, for example, length or hasOwnProperty, 127 00:05:53,140 --> 00:05:55,810 ‫and all these kinds of methods here 128 00:05:55,810 --> 00:05:58,330 ‫that we know already, right? 129 00:05:58,330 --> 00:06:00,470 ‫And now, to exit the REPL, 130 00:06:00,470 --> 00:06:03,863 ‫remember all you have to do is hit control D. 131 00:06:04,882 --> 00:06:08,700 ‫Okay, then command K to clear the console, 132 00:06:08,700 --> 00:06:10,200 ‫and that's it. 133 00:06:10,200 --> 00:06:12,230 ‫So that's all I wanted to show you 134 00:06:12,230 --> 00:06:14,680 ‫in this very, very first video. 135 00:06:14,680 --> 00:06:17,530 ‫So basically that we can write JavaScript now 136 00:06:17,530 --> 00:06:21,603 ‫outside of the browser using Node.js like this.