1 00:00:01,790 --> 00:00:02,623 There's a new, 2 00:00:02,623 --> 00:00:06,430 very simple array method in ES2022, 3 00:00:06,430 --> 00:00:08,550 which is the At Method. 4 00:00:08,550 --> 00:00:10,513 And so let's take a look at it. 5 00:00:12,400 --> 00:00:16,063 And let's start by creating some dummy array. 6 00:00:17,240 --> 00:00:22,240 So, 23, 11, 64. 7 00:00:22,670 --> 00:00:25,260 So just three random values here. 8 00:00:25,260 --> 00:00:28,400 And then, if we wanted to take one of the values 9 00:00:28,400 --> 00:00:29,850 out of the array, 10 00:00:29,850 --> 00:00:31,483 let's say the first one, 11 00:00:32,870 --> 00:00:37,410 then we would traditionally do this, right? 12 00:00:37,410 --> 00:00:40,630 So array at position zero. 13 00:00:40,630 --> 00:00:42,810 So that's basically what this means. 14 00:00:42,810 --> 00:00:45,290 But now with the new At Method, 15 00:00:45,290 --> 00:00:49,300 we can do the exact same thing using a method. 16 00:00:49,300 --> 00:00:52,623 And, as you can guess, that is the At Method. 17 00:00:54,220 --> 00:00:57,510 Then we specify the exact same index here, 18 00:00:57,510 --> 00:00:59,633 and then we get the exact same value. 19 00:01:00,750 --> 00:01:04,590 So basically now we do what we say here. 20 00:01:04,590 --> 00:01:07,950 So here we say, array at position zero. 21 00:01:07,950 --> 00:01:10,360 And so that's why this new method is called 22 00:01:10,360 --> 00:01:13,950 array dot at position zero. 23 00:01:13,950 --> 00:01:17,020 So very, very simple, right? 24 00:01:17,020 --> 00:01:19,020 So basically we can now replace 25 00:01:19,020 --> 00:01:21,040 the traditional bracket notation 26 00:01:21,040 --> 00:01:24,040 with the more modern looking At Method, 27 00:01:24,040 --> 00:01:27,363 if we prefer to use array methods like this. 28 00:01:28,220 --> 00:01:31,280 Now, maybe this doesn't look all too useful. 29 00:01:31,280 --> 00:01:33,950 So, what's the big deal here? 30 00:01:33,950 --> 00:01:38,750 Well, actually there is one particularity of the At Method, 31 00:01:38,750 --> 00:01:41,330 which makes it quite useful to use 32 00:01:41,330 --> 00:01:43,703 instead of the brackets notation. 33 00:01:44,750 --> 00:01:47,650 So, let's now say that we wanted to get 34 00:01:47,650 --> 00:01:50,620 the last element of the array. 35 00:01:50,620 --> 00:01:55,003 Now, supposing that we do not know the length of the array, 36 00:01:56,370 --> 00:01:58,343 we would write something like this. 37 00:01:59,900 --> 00:02:02,570 So, array at the position of 38 00:02:02,570 --> 00:02:06,823 array dot length minus one. 39 00:02:07,880 --> 00:02:10,053 And that will then give us 64. 40 00:02:11,640 --> 00:02:14,840 So, array dot length is the length of the array, 41 00:02:14,840 --> 00:02:16,160 which a three, 42 00:02:16,160 --> 00:02:19,670 but the last position here is position number two 43 00:02:19,670 --> 00:02:22,190 because the array is zero-based. 44 00:02:22,190 --> 00:02:24,230 So the indexes are zero-based. 45 00:02:24,230 --> 00:02:26,580 So zero, one, two. 46 00:02:26,580 --> 00:02:27,530 And so therefore, 47 00:02:27,530 --> 00:02:30,740 whenever we want to get the last element of an array, 48 00:02:30,740 --> 00:02:34,370 we always subtract one from the length. 49 00:02:34,370 --> 00:02:37,710 So this is quite a common scenario in JavaScript. 50 00:02:37,710 --> 00:02:40,293 And that's why there's also another solution. 51 00:02:42,810 --> 00:02:46,303 So another way is to use the slice method 52 00:02:46,303 --> 00:02:48,083 that we just learned before. 53 00:02:49,520 --> 00:02:51,300 So arr dot slice. 54 00:02:51,300 --> 00:02:52,133 And with this, 55 00:02:52,133 --> 00:02:55,000 we can then get a copy of the original array. 56 00:02:55,000 --> 00:02:57,850 And here we can use minus one to get 57 00:02:57,850 --> 00:03:01,380 the last element of the array, right? 58 00:03:01,380 --> 00:03:03,780 So just like we learned in the previous lecture. 59 00:03:05,720 --> 00:03:08,400 So, here we get that copy of the array 60 00:03:08,400 --> 00:03:10,900 only with the last element. 61 00:03:10,900 --> 00:03:12,600 So of course we want the value, 62 00:03:12,600 --> 00:03:15,658 and so then we need to take out that first value 63 00:03:15,658 --> 00:03:18,733 by doing square brackets zero. 64 00:03:20,240 --> 00:03:21,300 Now, right. 65 00:03:21,300 --> 00:03:24,370 So these are the two more traditional ways of solving 66 00:03:24,370 --> 00:03:27,503 the problem of getting the last element. 67 00:03:31,370 --> 00:03:34,140 However, as you can probably guess, 68 00:03:34,140 --> 00:03:38,080 the new At Method makes this process even easier. 69 00:03:38,080 --> 00:03:43,010 So now all we have to do is to write arr dot at, 70 00:03:43,010 --> 00:03:47,050 and now here we can write the exact same negative in nexus, 71 00:03:47,050 --> 00:03:51,030 then we can write in the slice method. 72 00:03:51,030 --> 00:03:52,860 And so if we lock this now, 73 00:03:52,860 --> 00:03:55,293 then here again we have 64. 74 00:03:56,210 --> 00:03:59,390 So the negative index, just like in slice, 75 00:03:59,390 --> 00:04:03,140 basically starts counting from the right side here. 76 00:04:03,140 --> 00:04:05,340 So from the end of the array. 77 00:04:05,340 --> 00:04:08,580 And so we could also write, minus two. 78 00:04:08,580 --> 00:04:12,050 So, minus one and minus two. 79 00:04:12,050 --> 00:04:14,240 So this should give us 11. 80 00:04:14,240 --> 00:04:17,050 And indeed here is that 11. 81 00:04:17,050 --> 00:04:18,410 But most of the time, 82 00:04:18,410 --> 00:04:20,880 the thing that we're most interested in here 83 00:04:20,880 --> 00:04:25,620 is this minus one, to get the last element of the array. 84 00:04:25,620 --> 00:04:27,540 And that's actually it. 85 00:04:27,540 --> 00:04:29,140 Now the only question is, 86 00:04:29,140 --> 00:04:31,680 should you use this new At Method 87 00:04:31,680 --> 00:04:34,818 or should you keep using the bracket notation? 88 00:04:34,818 --> 00:04:38,300 Well, as always, it depends. 89 00:04:38,300 --> 00:04:41,610 So, if you want to get to the last element of an array, 90 00:04:41,610 --> 00:04:45,480 or basically start counting from the end of an array, 91 00:04:45,480 --> 00:04:49,100 then you should probably start using the At Method. 92 00:04:49,100 --> 00:04:52,830 Also, if you want to do something called "method chaining", 93 00:04:52,830 --> 00:04:55,690 which we will talk about later in this section, 94 00:04:55,690 --> 00:04:59,120 then the At Method is also perfect for that. 95 00:04:59,120 --> 00:05:01,610 So basically combining multiple methods 96 00:05:01,610 --> 00:05:03,200 all at the same time. 97 00:05:03,200 --> 00:05:05,890 And then, it's quite helpful to use 98 00:05:05,890 --> 00:05:09,330 the At Method instead of the brackets notation. 99 00:05:09,330 --> 00:05:10,630 Now, on the other hand, 100 00:05:10,630 --> 00:05:14,250 if you just want to quickly get a value from an array, 101 00:05:14,250 --> 00:05:16,670 so just like the first element, 102 00:05:16,670 --> 00:05:19,770 then of course you can keep using the brackets notation. 103 00:05:19,770 --> 00:05:22,860 And personally, I also do that all the time. 104 00:05:22,860 --> 00:05:26,010 So basically if all you want to do is something like this, 105 00:05:26,010 --> 00:05:29,343 then you can simply keep using the square brackets. 106 00:05:30,320 --> 00:05:31,700 Okay. 107 00:05:31,700 --> 00:05:33,620 Oh, and by the way, 108 00:05:33,620 --> 00:05:37,170 I actually also wanted to let you know that the At Method 109 00:05:37,170 --> 00:05:39,013 also works on strings. 110 00:05:40,690 --> 00:05:43,080 So, let's look to the console. 111 00:05:43,080 --> 00:05:43,923 A string, 112 00:05:45,010 --> 00:05:47,790 let's say jonas and then here we can also use 113 00:05:47,790 --> 00:05:48,823 the At Method. 114 00:05:49,690 --> 00:05:51,640 For example, let's say, at zero. 115 00:05:51,640 --> 00:05:54,233 And so that will give us J, 116 00:05:55,720 --> 00:05:57,610 and then of course we can also 117 00:05:57,610 --> 00:05:59,900 get the last character off the string 118 00:05:59,900 --> 00:06:01,633 by using at minus one.