1 00:00:00,920 --> 00:00:04,400 This video is about accessing. 2 00:00:05,280 --> 00:00:06,870 I raised goat. 3 00:00:06,880 --> 00:00:10,380 So let me comment out this. 4 00:00:11,730 --> 00:00:12,600 Like that. 5 00:00:12,600 --> 00:00:15,240 And now let's calm down here. 6 00:00:17,150 --> 00:00:19,370 As accessing. 7 00:00:20,470 --> 00:00:21,430 I read. 8 00:00:22,630 --> 00:00:25,250 Okay, so let's declare a variable cost. 9 00:00:25,270 --> 00:00:28,990 Let's say books array is equal to. 10 00:00:29,020 --> 00:00:35,440 Now we are going to take the easiest way that is using the square brackets without using the new. 11 00:00:35,470 --> 00:00:38,010 I mean, the new syntax or the new keyword. 12 00:00:38,020 --> 00:00:39,740 So this is the easy way to go. 13 00:00:39,760 --> 00:00:44,230 So let's say that I want to save MongoDB into this. 14 00:00:45,040 --> 00:00:53,080 After that, Node.js is not period, but instead is comma comma separated. 15 00:00:53,290 --> 00:00:58,810 The next one is I also want to save React JS into it. 16 00:00:58,990 --> 00:01:00,880 So this is my book what? 17 00:01:00,910 --> 00:01:02,290 My book array. 18 00:01:02,320 --> 00:01:09,220 Now if I check my books here we see that I have the red code inside this. 19 00:01:09,520 --> 00:01:14,320 And as before, how can we access array? 20 00:01:14,860 --> 00:01:19,000 Well, we have two ways of accessing arrays. 21 00:01:19,030 --> 00:01:21,910 That is using the. 22 00:01:22,900 --> 00:01:26,050 Index of heart rate. 23 00:01:26,140 --> 00:01:29,500 And that is what I have explained before over here. 24 00:01:29,770 --> 00:01:37,510 So for this one, if we want to access, let's say, this book, you refer by eight index. 25 00:01:37,510 --> 00:01:43,540 So let's come down here, let's say get first book. 26 00:01:45,070 --> 00:01:45,940 First. 27 00:01:47,110 --> 00:01:47,730 Book. 28 00:01:47,740 --> 00:01:48,760 So here you go. 29 00:01:48,940 --> 00:01:49,870 So. 30 00:01:50,690 --> 00:01:55,190 Books and then my square bracket and then zero. 31 00:01:55,280 --> 00:01:56,600 That's my first book. 32 00:01:56,720 --> 00:02:05,720 Okay, so I can assign this one to, let's say cost, let's say book one as B one, book one. 33 00:02:05,720 --> 00:02:10,610 So if I console that log book one, that is my B one. 34 00:02:10,610 --> 00:02:13,130 I have MongoDB here. 35 00:02:13,550 --> 00:02:18,620 So if I want access, second book, third book and the fourth book. 36 00:02:18,620 --> 00:02:22,050 So let's access second book. 37 00:02:22,070 --> 00:02:31,640 So the second book is going to be B two here and now second book will be at index one because the zero 38 00:02:31,640 --> 00:02:32,240 base. 39 00:02:32,420 --> 00:02:35,300 So if I check for book two here. 40 00:02:36,190 --> 00:02:37,090 Like that. 41 00:02:37,180 --> 00:02:40,150 So can you access book three? 42 00:02:40,360 --> 00:02:44,380 Well, you can put this video and then try your luck on that. 43 00:02:44,560 --> 00:02:49,770 So book three, I can copy this one and say this is my book three. 44 00:02:49,780 --> 00:02:54,430 I want access at index two and then book four. 45 00:02:55,840 --> 00:02:57,250 Here are going to be three. 46 00:02:58,180 --> 00:02:59,980 And then here are going to be. 47 00:03:01,310 --> 00:03:02,020 Four. 48 00:03:02,060 --> 00:03:06,500 So here is going to be B to B three and then B four. 49 00:03:06,860 --> 00:03:11,240 So if I search for B. 50 00:03:11,920 --> 00:03:12,780 Two. 51 00:03:12,820 --> 00:03:13,930 I have no jazz. 52 00:03:13,960 --> 00:03:17,130 If I search for B three, I have react. 53 00:03:17,140 --> 00:03:22,030 If I access B four, I have no jazz. 54 00:03:22,120 --> 00:03:27,850 What about if I'm trying to access a data that is inside my array? 55 00:03:27,880 --> 00:03:29,680 What is going to return? 56 00:03:30,040 --> 00:03:34,170 So let's say that I want access for this one before you're going to be with three. 57 00:03:34,180 --> 00:03:34,930 Sorry, guys. 58 00:03:35,110 --> 00:03:38,440 Let's say I want to access index seven here. 59 00:03:39,140 --> 00:03:42,060 Do we have index screen here inside this one node? 60 00:03:42,080 --> 00:03:49,570 So if I console that, log the book for let's see the book four, we see that I get undefined. 61 00:03:49,580 --> 00:03:59,540 So it means that if a record that you are trying to access is not inside, the array is going to retain 62 00:03:59,540 --> 00:04:01,040 undefined. 63 00:04:01,550 --> 00:04:02,750 All right, the next video. 64 00:04:02,750 --> 00:04:07,160 Let's see how we can attract over an array.