WEBVTT 00:00.980 --> 00:01.520 Hi everyone. 00:01.520 --> 00:02.780 Welcome back to this tutorial. 00:02.780 --> 00:06.500 In this tutorial, we will explore the numeric streams. 00:06.500 --> 00:09.080 What are numeric streams in the first place? 00:09.110 --> 00:15.140 Numeric streams are used to represent the primitive values in a stream. 00:15.320 --> 00:16.640 There are three different types. 00:16.640 --> 00:20.480 One is a stream, long stream and double stream. 00:20.510 --> 00:26.150 I would like to explain the advantages of numeric stream over the regular stream. 00:26.150 --> 00:29.840 Using an example, let's go back to the IntelliJ and code this one. 00:31.770 --> 00:36.240 Then here what I'm going to do, the first step is I'm going to create a package called. 00:38.260 --> 00:39.430 Numeric streams. 00:40.350 --> 00:43.530 And then I'm going to create a class called. 00:45.440 --> 00:46.250 Numeric. 00:47.460 --> 00:48.780 Reims example. 00:50.920 --> 00:54.370 Make this class executable by adding public static void main method. 00:58.100 --> 01:03.470 So the use case that we are going to code, we are going to perform sum of N numbers. 01:03.860 --> 01:08.360 The first step is I'm going to build the input list. 01:09.140 --> 01:10.340 List of integer. 01:11.210 --> 01:12.500 Let's import this one. 01:13.940 --> 01:14.840 And then. 01:16.200 --> 01:17.460 Start an integer list. 01:18.470 --> 01:18.890 Its name. 01:18.890 --> 01:22.340 This one as arrays, dot as list. 01:22.370 --> 01:26.370 Basically, we are going to create a integer list. 01:26.390 --> 01:29.090 I'm going to provide the input values. 01:30.450 --> 01:30.960 There you go. 01:30.960 --> 01:32.640 We have the input list ready. 01:32.730 --> 01:34.350 I'm going to create a method here. 01:34.830 --> 01:41.160 The method is going to perform sum of N numbers and return the sum as a result. 01:42.510 --> 01:43.080 Some of. 01:44.140 --> 01:45.040 In numbers. 01:47.120 --> 01:49.790 And it is going to take in this input. 01:50.780 --> 01:52.040 List of integers. 01:52.070 --> 01:54.430 As a method parameter. 01:54.440 --> 01:57.740 And in here we are going to perform the summation. 01:57.740 --> 02:01.550 Here we are going to use the reduce function, which is part of the streams API. 02:01.580 --> 02:08.660 The first step is we are going to create the stream and then let's use the reduce method. 02:08.960 --> 02:14.690 The reduce method is going to take in a default value, meaning the initial value. 02:14.690 --> 02:19.880 And then we are going to perform sum of two numbers. 02:20.990 --> 02:22.220 Then X plus Y. 02:24.440 --> 02:25.880 Then I'm going to return this method. 02:28.820 --> 02:30.180 For a keyboard return. 02:31.390 --> 02:31.680 Here. 02:31.690 --> 02:33.850 Let's print the result and then check the result. 02:35.470 --> 02:38.440 Sum of numbers. 02:39.630 --> 02:41.400 And here we are going to. 02:42.380 --> 02:45.350 All this method and pass the integer list as an input. 02:46.100 --> 02:48.320 Let's run this and validate the result. 02:49.650 --> 02:50.760 Tony's run the program. 02:50.760 --> 02:56.600 It gave me the result as sum of N numbers, so we got the desired result. 02:56.610 --> 02:58.590 But there is a problem with this code. 02:58.590 --> 03:03.720 Actually, if you take a look at it, we are passing a list of integer. 03:03.720 --> 03:08.250 Integer is a wrapper class for the int primitive type. 03:08.250 --> 03:10.290 So what happens behind the scenes? 03:10.290 --> 03:19.350 Basically under the hood it performs the unboxing operation to convert the integer to int. 03:19.530 --> 03:21.570 So there is some wasted effort here. 03:21.570 --> 03:28.980 So every time it the stream passes an element it is going to perform unboxing of that integer, converting 03:28.980 --> 03:34.650 this integer wrapper class to a int primitive type and then perform the summation and return the result. 03:35.040 --> 03:37.740 So how can we avoid this? 03:37.740 --> 03:40.650 That's where the end stream comes into picture. 03:40.680 --> 03:44.370 I'm going to create a method called public static int. 03:46.340 --> 03:47.180 Some of. 03:48.050 --> 03:48.900 In numbers. 03:48.920 --> 03:49.850 INT string. 03:51.920 --> 03:56.300 So end stream as a handy method called in stream. 03:56.300 --> 03:56.630 There you go. 03:56.630 --> 04:03.200 It is part of the java.util dot stream package dot, and then it has a method called range closed. 04:03.650 --> 04:09.140 So we will cover this range closed and ranges as a separate tutorial in the next tutorial. 04:09.170 --> 04:11.960 But for now you can use this range closed. 04:11.990 --> 04:20.150 Basically this is going to give you one, two, three, four, five, six is going to give you six integers. 04:21.130 --> 04:23.980 And then we are going to perform a sub method. 04:25.720 --> 04:26.860 It has a lot of other methods. 04:26.860 --> 04:28.960 We'll be exploring all the different methods. 04:28.990 --> 04:30.220 The following tutorials. 04:30.220 --> 04:35.230 For now, our use case is going to be we are going to perform the sum of N numbers. 04:36.750 --> 04:37.890 And I'm going to return this. 04:39.670 --> 04:42.460 And if you take a look at it, one more thing here. 04:42.460 --> 04:44.050 We had to call the stream method. 04:44.080 --> 04:46.420 But in here we did not call the stream method. 04:46.450 --> 04:53.200 The reason being if you go to this range closed, the return type of this range closed is in stream. 04:53.410 --> 04:55.470 That is something which we have to keep in our mind. 04:55.480 --> 05:01.450 It already creates a stream and gives you the stream and this is going to pass the values one by one, 05:01.990 --> 05:03.820 one to. 05:05.560 --> 05:05.950 Three. 05:07.550 --> 05:08.060 For. 05:09.320 --> 05:11.080 Five and six. 05:11.090 --> 05:17.060 The Sun mother is going to get the values one by one and then perform the accumulation of the result 05:17.060 --> 05:19.640 and return the result as a output. 05:22.460 --> 05:23.750 I'm of in numbers. 05:24.950 --> 05:25.970 Using end. 05:27.210 --> 05:27.470 Bring. 05:29.940 --> 05:30.160 So. 05:31.490 --> 05:31.780 Dream. 05:31.790 --> 05:33.680 I don't have to pass any input to that method. 05:33.680 --> 05:38.150 It is just going to be an empty method, meaning empty input method. 05:38.930 --> 05:40.700 Let's run this and check the result. 05:41.740 --> 05:42.280 There you go. 05:42.310 --> 05:44.710 It printed the same result. 05:45.310 --> 05:52.720 So under scenarios where you are going to perform number related operations, then you can make use 05:52.720 --> 05:56.650 of the numeric streams instead of the regular streams. 05:56.680 --> 05:58.750 With this, we came to the end of this tutorial. 05:58.780 --> 05:59.950 Thank you for watching.