WEBVTT 00:00.110 --> 00:00.650 Hi everyone. 00:00.650 --> 00:01.880 Welcome back to this tutorial. 00:01.880 --> 00:07.790 In this tutorial, we will code and explore a scenario where your collection value is null, but you're 00:07.790 --> 00:12.860 trying to perform the sort using the comparator on that collection for that purpose. 00:12.860 --> 00:19.700 What I'm going to do, I'm going to use the default methods example to class and then in the get all 00:19.700 --> 00:20.570 students. 00:21.810 --> 00:23.370 Let me put this in presentation mode. 00:26.290 --> 00:30.250 Your collection element is going to have a null, right? 00:31.400 --> 00:33.620 And then if you try to perform. 00:34.770 --> 00:36.450 Here we are calling the comparator training. 00:36.450 --> 00:36.660 Right? 00:36.660 --> 00:39.030 Let's go ahead and run this and then see what happens. 00:40.250 --> 00:43.850 If you try to run it, you're going to get the null pointer exception. 00:43.880 --> 00:49.190 How do we handle these kind of scenarios when you're trying to perform a sort? 00:49.220 --> 00:55.940 Using the comparator comparator as a handy method called nulls first, nulls last, we are going to 00:55.940 --> 00:57.080 go ahead and explore that. 00:58.390 --> 01:02.170 I'm going to name this method as public static void. 01:03.390 --> 01:04.110 Sort. 01:06.680 --> 01:07.970 It null values. 01:12.740 --> 01:16.190 So just going to accept the list of students. 01:18.820 --> 01:20.290 Trying to be student list. 01:21.300 --> 01:25.500 And then what we are going to do, we are going to perform the. 01:26.280 --> 01:26.580 Null. 01:26.580 --> 01:27.030 Check here. 01:27.030 --> 01:31.320 We're going to perform the sort on this list which has a null value. 01:32.100 --> 01:32.520 How do do. 01:33.030 --> 01:35.040 So comparator. 01:37.340 --> 01:45.320 Create an instance of comparator has a method called nulls as last nulls as first I'm going to use nulls 01:45.500 --> 01:49.910 first method and then this is going to take in a comparator. 01:49.910 --> 01:52.310 So we are going to use the name comparator. 01:52.310 --> 01:55.460 We are going to basically sort the collection by name. 01:56.380 --> 01:57.370 Let's give it a name. 01:57.370 --> 01:58.570 Comparator. 02:00.510 --> 02:03.480 Student and then student comparator. 02:05.310 --> 02:10.560 Okay, now what we are going to do, we are going to do Student Comparator dot. 02:11.750 --> 02:14.120 Now the certain competitor, the student list. 02:15.240 --> 02:19.140 Dot chart and pass the student comparator. 02:19.710 --> 02:28.650 Now, instead of calling this, I'm going to call the dot with null values and student list. 02:29.600 --> 02:37.040 Okay, Now what we will do, we will call the consumer and then get the result printed in the console. 02:38.020 --> 02:39.100 Let's run this. 02:40.360 --> 02:42.310 Do you see any nullpointerexception here? 02:42.340 --> 02:43.840 No null pointer exception. 02:43.840 --> 02:45.830 And then it printed the result. 02:45.850 --> 02:47.860 I'm going to have a code comment here. 02:50.430 --> 02:52.050 Is going to be after. 02:52.840 --> 02:53.380 Thought. 02:54.410 --> 02:55.550 But null values. 02:57.030 --> 02:58.440 On this example again. 02:58.710 --> 03:03.600 So the program executed without any issues, but let's validate what's happening with the result. 03:03.630 --> 03:07.050 In the result, if you take a look at it, this is a before shot. 03:07.080 --> 03:13.440 In the before shot, we have the null value towards the end because that's where we added the null value 03:13.440 --> 03:14.190 to the collection. 03:14.190 --> 03:18.420 So the array list has a null value added as a last element. 03:19.120 --> 03:19.740 Into it. 03:19.750 --> 03:20.440 Right. 03:20.440 --> 03:27.070 But in the short operation, what we are doing is we are asking the null value to be present at the 03:27.070 --> 03:27.790 first element. 03:27.820 --> 03:30.280 That's the reason why we are calling the nulls first. 03:30.310 --> 03:34.000 If you call nulls last, what will happen? 03:34.000 --> 03:37.270 So this null value will be pushed towards the end. 03:37.690 --> 03:38.890 That's what is going to happen. 03:38.890 --> 03:40.090 Let's go ahead and run this. 03:42.000 --> 03:42.930 Take a look at the result. 03:42.930 --> 03:47.850 The after sort with null values pushed the null value towards the end. 03:48.030 --> 03:52.770 So this is one handy way of handling the null values. 03:52.770 --> 03:57.180 If your collection is going to hold a null value in it. 03:58.590 --> 03:58.890 With this. 03:58.890 --> 04:00.510 We came to the end of this tutorial. 04:00.540 --> 04:01.620 Thank you for watching.