1 00:00:00,440 --> 00:00:06,850 ‫So now we're going to create our pre penned function and pre penned is going to look like this. 2 00:00:06,860 --> 00:00:09,020 ‫We'll create a new node. 3 00:00:09,290 --> 00:00:17,990 ‫We will point that new node at the first node by setting it equal to head, and they will have head 4 00:00:17,990 --> 00:00:19,340 ‫point at that new node. 5 00:00:19,340 --> 00:00:22,010 ‫And that adds that into the linked list. 6 00:00:22,400 --> 00:00:25,490 ‫That's how it works if we have items in the linked list. 7 00:00:25,490 --> 00:00:31,760 ‫But if we have an empty linked list, we'll have head and tail point to that new node. 8 00:00:32,210 --> 00:00:37,210 ‫So we'll start off that function like this will pass it a value. 9 00:00:37,220 --> 00:00:42,170 ‫We'll use that value to create a node like this. 10 00:00:42,560 --> 00:00:48,710 ‫So the next thing we'll code for is when we have an empty linked list where we have head and tail point 11 00:00:48,710 --> 00:00:49,970 ‫to that new node. 12 00:00:50,210 --> 00:00:55,400 ‫But the first thing we need to do is test to see is the length list empty. 13 00:00:55,700 --> 00:00:58,900 ‫So we'll say if length is equal to zero. 14 00:00:58,910 --> 00:01:06,590 ‫And you could also say if head is equal to null pointer, then we'll set head to be equal to new node 15 00:01:06,590 --> 00:01:13,010 ‫like this and then we'll set tail to be equal to new node like this. 16 00:01:13,340 --> 00:01:16,580 ‫So let's add this in with the rest of our code. 17 00:01:16,790 --> 00:01:21,920 ‫So now let's code for when we do have items in the length list, we'll say else. 18 00:01:21,920 --> 00:01:25,130 ‫And now let's build out this else statement. 19 00:01:25,970 --> 00:01:29,780 ‫We'll say new node next equals head. 20 00:01:30,350 --> 00:01:35,510 ‫That's going to do this and point that node to the first node in the linked list. 21 00:01:36,210 --> 00:01:42,930 ‫Then we'll say head equals new node and that moves head over like this and adds this into the length 22 00:01:42,930 --> 00:01:43,590 ‫list. 23 00:01:44,010 --> 00:01:50,280 ‫So now let's add this and with the rest of our code and the only other thing that we need to do is to 24 00:01:50,280 --> 00:01:52,620 ‫increase the length by one. 25 00:01:52,920 --> 00:01:56,130 ‫So we'll look at this code in a moment and vs code. 26 00:01:56,130 --> 00:02:04,140 ‫And when we do we're going to create this length list with two and three and then we will pretend a 27 00:02:04,140 --> 00:02:09,150 ‫node with a value of one and our linked list will be one, two, three. 28 00:02:09,540 --> 00:02:13,170 ‫So now let's go take a look at this NVS code. 29 00:02:14,080 --> 00:02:21,160 ‫So there is our pre pin function there and I'll scroll up so we can take a look at our main function. 30 00:02:21,550 --> 00:02:27,880 ‫And this creates our linked list with two nodes with a values of two and three, and then with this 31 00:02:27,880 --> 00:02:31,030 ‫line will print this out and I'll run this. 32 00:02:31,600 --> 00:02:36,520 ‫And you can see up here that our linked list has values of two and three. 33 00:02:37,150 --> 00:02:39,790 ‫So I'm going to come up here and add a line. 34 00:02:40,910 --> 00:02:47,960 ‫And with this line we'll pretend a node with a value of one and they will print this out again and I'll 35 00:02:47,960 --> 00:02:49,430 ‫run this. 36 00:02:50,060 --> 00:02:55,190 ‫And now you can see our linked list has values of one, two and three. 37 00:02:56,090 --> 00:02:59,990 ‫And that is our function for pretend.