WEBVTT 00:00.880 --> 00:01.480 Hi everyone. 00:01.480 --> 00:02.770 Welcome back to this tutorial. 00:02.770 --> 00:08.020 In this tutorial we will code and explore the default methods that got introduced as part of the list 00:08.020 --> 00:09.010 interface. 00:09.070 --> 00:15.670 For this purpose, what I'm going to do, I'm going to create a package called defaults. 00:16.210 --> 00:26.170 And then the next step is I'm going to create a class called Default Methods example. 00:26.830 --> 00:33.280 The next step is we are going to make this class executable by adding public static void main. 00:37.130 --> 00:38.570 Now the use cases. 00:39.790 --> 00:41.770 Sort the list of names. 00:42.950 --> 00:45.560 Basically, which are nothing but a list of strings. 00:46.370 --> 00:47.780 In alphabetical order. 00:49.230 --> 00:51.690 I'm just keeping this use case really simple. 00:53.350 --> 00:56.830 Now, the first step is we need to create the input list, right? 00:56.860 --> 00:58.870 Let's give a list of string. 01:01.750 --> 01:04.420 And then let's give it a name called String list. 01:04.810 --> 01:06.520 First up is we'll import this. 01:07.550 --> 01:14.900 As part of the Java.util package and we are going to use the arrays class dot as list. 01:15.140 --> 01:17.000 I'm going to give some list of names. 01:17.030 --> 01:19.220 The names are going to be Adam. 01:20.320 --> 01:22.240 The next one is going to be Jenny. 01:29.810 --> 01:30.410 Mike. 01:31.860 --> 01:32.250 Then. 01:33.680 --> 01:34.010 Rick. 01:35.090 --> 01:37.100 So the list is not in. 01:38.010 --> 01:38.640 Dotted order. 01:38.640 --> 01:43.050 Basically, we are going to start this list in alphabetical order. 01:43.200 --> 01:50.460 Let's talk about the prior Java eight way and then we will explore the new Java eight way using the 01:50.460 --> 01:53.610 default method that is part of the list interface itself. 01:55.870 --> 01:59.020 Are some code comments here prior to Java eight. 02:00.070 --> 02:01.600 Now the first purpose. 02:02.550 --> 02:04.050 Let's use a collections class. 02:04.050 --> 02:10.350 That is a way we normally do use a collection class collections class and then call the sort method 02:10.350 --> 02:13.020 and pass this input list as an input. 02:13.050 --> 02:19.800 So this is going to sort the result, basically sort the input in alphabetical order and give you the 02:19.800 --> 02:20.370 result. 02:22.430 --> 02:23.480 What comments here? 02:25.660 --> 02:26.650 Dotted list. 02:28.270 --> 02:29.080 Using. 02:32.080 --> 02:33.040 Elections. 02:35.630 --> 02:36.830 Dot sort method. 02:38.100 --> 02:38.640 Right. 02:38.820 --> 02:41.280 Then let's print the result in English. 02:41.910 --> 02:42.390 There you go. 02:42.420 --> 02:44.640 Now I'm going to run this program. 02:45.870 --> 02:47.640 Run default methods example. 02:48.210 --> 02:49.170 There we go. 02:49.920 --> 02:50.700 Gave you the result. 02:50.700 --> 02:54.090 If you take a look at the result, the result is in sorted order. 02:54.330 --> 02:55.590 We take a look at the Alex. 02:55.620 --> 02:59.490 Alex is at the third position, but here Alex is at the second position. 02:59.970 --> 03:04.380 The whole input list is sorted in ascending order. 03:04.380 --> 03:07.890 Now let's talk about the Java eight approach. 03:10.440 --> 03:11.660 So in Java eight. 03:12.820 --> 03:14.290 The list interface here. 03:14.320 --> 03:15.730 Go to the list interface. 03:15.970 --> 03:16.900 This is an interface. 03:16.900 --> 03:23.020 The list interface has a lot of default methods in it that got introduced as part of Java eight. 03:23.020 --> 03:30.220 And let's take a look at the methods, whatever that got introduced as part of the list interface. 03:31.480 --> 03:36.940 As soon as we dot is going to give you a lot of methods and sort is one of them. 03:36.940 --> 03:37.990 I'm going to select that. 03:39.370 --> 03:40.420 You go to this method. 03:40.750 --> 03:43.990 This method takes an input called comparator. 03:44.110 --> 03:50.980 But if you take a look at it, this is a default keyword which I was referring to in our presentation, 03:50.980 --> 03:55.510 and this default keyword got introduced as part of Java 1.8. 03:56.050 --> 03:56.800 We take a look at it. 03:56.800 --> 03:59.800 Interfaces now have a complete method. 03:59.800 --> 04:02.770 Implementation was never possible before Java eight. 04:02.800 --> 04:06.030 You can take a look at some of the prior methods in the list interface. 04:06.040 --> 04:12.400 This is again another default method which got introduced as part of Java eight in list interface. 04:13.150 --> 04:16.540 And if you take a look at this one, do you see any method implementation here? 04:17.350 --> 04:19.450 This is just declaring the method. 04:19.480 --> 04:24.800 The array list implementation of this list interface will implement the logic behind this. 04:24.850 --> 04:31.780 So now with the introduction of default methods, ideally this is helping the Java creators to introduce 04:31.780 --> 04:39.520 new functionalities into the interfaces so that this interface can evolve according to the technology 04:39.520 --> 04:41.980 advancements and new use cases. 04:42.370 --> 04:47.350 Now what we are going to do, the Sort method takes an input called comparator. 04:47.350 --> 04:53.020 So we are going to create a comparator here, take a look at the comparator, has a comparing method, 04:53.020 --> 04:55.000 but we are not going to use that method. 04:56.080 --> 04:59.380 Comparator are something called the natural order. 04:59.410 --> 05:08.320 The natural order is something which is going to inform the Sort method to sort the result in ascending 05:08.320 --> 05:08.920 order. 05:09.250 --> 05:14.080 Order to make sure this isn't going to impact our sort operation here. 05:14.080 --> 05:15.640 I'm going to comment this code. 05:15.910 --> 05:17.830 Now let's run this and check the result. 05:17.830 --> 05:19.390 I'm going to copy this same. 05:23.720 --> 05:28.970 And then I'm going to give it a different name because we are using the sort method that is part of 05:28.970 --> 05:30.680 the list interface. 05:30.710 --> 05:34.280 Now what I'm going to do, I'm going to run this and check the result. 05:35.650 --> 05:36.160 There you go. 05:36.250 --> 05:36.890 Take a look at it. 05:36.910 --> 05:39.300 It gave you the same result as before. 05:39.310 --> 05:46.270 But if you are using the sort method that is part of the list interface, and this sort method is a 05:46.270 --> 05:50.140 default method that is part of the list interface. 05:51.110 --> 05:51.640 No. 05:51.650 --> 05:54.350 You want to reverse the result? 05:54.380 --> 05:55.430 How do we do it? 05:55.700 --> 06:01.310 So if we take a look at it start method, we are going to use the same start method, but we are going 06:01.310 --> 06:04.050 to change the comparator implementation. 06:04.070 --> 06:06.580 So here we are going to pass a reverse order. 06:06.590 --> 06:11.240 What this is going to do, this is going to reverse the result. 06:14.210 --> 06:15.010 And thus. 06:17.430 --> 06:18.240 Take a look at it. 06:18.390 --> 06:21.840 It actually reversed the result, basically. 06:22.560 --> 06:24.190 This one is in alphabetical order. 06:24.210 --> 06:26.130 This one is in reverse order. 06:27.040 --> 06:33.520 So I would highly recommend you guys to explore the other default method, which is nothing but the 06:33.520 --> 06:34.600 replace all. 06:36.470 --> 06:38.510 Search for default in this one. 06:39.430 --> 06:44.590 Ideally it is giving you six matches, but actually there are three different methods that got introduced 06:44.590 --> 06:47.560 as part of the Java eight. 06:47.590 --> 06:49.520 So this is called Splitter Splitter. 06:50.110 --> 06:53.050 This can be used for parallel programming. 06:53.080 --> 06:55.090 We have seen the parallel streams, right? 06:55.090 --> 06:58.270 If you want to manually do it, then we can use Splitter. 06:58.500 --> 07:04.000 We'll discuss about this in one of the future tutorials, but for now just need to know, okay, these 07:04.000 --> 07:06.340 are the default methods that are part of the. 07:07.670 --> 07:11.750 This interface would highly recommend you guys to explore this. 07:13.740 --> 07:14.730 Go back to the code. 07:15.040 --> 07:15.170 Okay. 07:15.180 --> 07:17.300 With this, we came to the end of this tutorial. 07:17.310 --> 07:21.570 Let's explore another complex example in the next tutorial. 07:21.690 --> 07:22.890 Thank you for watching.