1 00:00:00,520 --> 00:00:05,950 Great job on making it this far into the U.S. You've made it to your first challenge of the section 2 00:00:06,070 --> 00:00:08,740 and that's to create a random array message. 3 00:00:08,950 --> 00:00:15,220 And what we've been looking at in the earlier lessons with random is ideal in order to select random 4 00:00:15,220 --> 00:00:16,660 items from the array. 5 00:00:16,810 --> 00:00:22,670 So selecting the index, we can randomly select any value randomly from the array. 6 00:00:22,810 --> 00:00:28,990 So we create an array, have a bunch of items in that array, and then selecting out a value that randomly 7 00:00:28,990 --> 00:00:32,710 from the array and then output it within the document. 8 00:00:32,830 --> 00:00:36,790 So appending the child to creating a text node in the depending it to the body. 9 00:00:36,790 --> 00:00:39,940 Pause the video here and I'll walk you through the solution. 10 00:00:40,860 --> 00:00:45,780 Great, I hope you had an opportunity to try this out, so first thing that we need is an array. 11 00:00:45,930 --> 00:00:49,020 This can be an array of anything you want. 12 00:00:49,290 --> 00:00:56,400 In this case, I'm going to have some hello messages and a welcome message and also bye bye message. 13 00:00:56,670 --> 00:01:01,250 And we don't know which one we're going to get because this is going to be returned back at random. 14 00:01:01,710 --> 00:01:07,900 Let's create a function in order to select an item from random and then we want to pass in the array. 15 00:01:07,920 --> 00:01:13,470 So again, trying to make it dynamic as possible, because I know we've got the array out here, but 16 00:01:13,470 --> 00:01:15,360 it's always better to be able to pass it in. 17 00:01:15,390 --> 00:01:16,980 So that gives you more flexibility. 18 00:01:17,100 --> 00:01:22,530 If you've got multiple arrays, you can use the same function in order to generate and return back a 19 00:01:22,530 --> 00:01:23,980 random item from the array. 20 00:01:24,390 --> 00:01:29,400 So it using the array object, we're returning back a value one of the index values. 21 00:01:29,410 --> 00:01:36,420 So if we want to return back one there, you can see that when I refresh and a random item and in this 22 00:01:36,420 --> 00:01:42,570 case it's passed the array, you can see that we get welcome being returned back because welcome is 23 00:01:42,570 --> 00:01:43,400 index one. 24 00:01:43,590 --> 00:01:47,190 And we also just saw that we could generate a random value. 25 00:01:47,370 --> 00:01:52,890 So let's create temporary value and using a math flaw. 26 00:01:53,490 --> 00:01:59,120 So always use math flaw and math random in combination and then math random. 27 00:01:59,130 --> 00:02:01,650 And what do we want to multiply math random by? 28 00:02:01,800 --> 00:02:04,340 We want to multiply it by the length of the array. 29 00:02:04,590 --> 00:02:08,400 So we don't want to we don't want to avoid as much hard coding as possible. 30 00:02:08,640 --> 00:02:13,740 And math flaw is ideal when you're working with arrays because arrays are zero index. 31 00:02:13,920 --> 00:02:17,750 So zero one two and we're not going to have three. 32 00:02:17,760 --> 00:02:20,250 So that's where my flaw brings that down. 33 00:02:20,460 --> 00:02:26,180 So we're turning back whatever the index value is, or replace one with the index and move that in. 34 00:02:26,190 --> 00:02:28,410 Let's clean that up and refresh. 35 00:02:28,560 --> 00:02:32,970 And now whenever I select a random number, don't forget, we need to pass in the array. 36 00:02:33,240 --> 00:02:36,230 We can get a random item coming from the array. 37 00:02:36,600 --> 00:02:42,870 So there's another part to this challenge, and that was to use this function and output the content 38 00:02:42,870 --> 00:02:45,450 into our HTML so that it's visible. 39 00:02:45,450 --> 00:02:48,690 So every time we load the page, we're going to have a different value there. 40 00:02:48,990 --> 00:02:51,330 So let's create another variable here. 41 00:02:51,330 --> 00:02:59,160 We can also call that temp because this is out of the scope of the function and using the random item 42 00:02:59,370 --> 00:03:01,370 passan the array object. 43 00:03:01,980 --> 00:03:06,140 So now temp will have any one of the values that's being returned message. 44 00:03:06,180 --> 00:03:07,130 So document. 45 00:03:07,140 --> 00:03:12,690 So creating a text node and the contents of the text node will be whatever is being returned back from 46 00:03:12,690 --> 00:03:21,180 the function and then using document body, we can append the child to the body so we can do is append 47 00:03:21,180 --> 00:03:21,800 the message. 48 00:03:22,080 --> 00:03:28,320 So now whenever we refresh, you can see that you've got this random value and this is coming out of 49 00:03:28,320 --> 00:03:28,820 the array. 50 00:03:29,190 --> 00:03:32,370 So doesn't matter how many times you refresh it, you're always going to get something different. 51 00:03:32,460 --> 00:03:36,360 Well, of course, sometimes you do get the same one because we only have the three items in the array. 52 00:03:36,840 --> 00:03:37,580 So try this out.