WEBVTT 0 00:00.140 --> 00:05.850 Hi everyone in this video I'm going to highlight a about why Java8 important and why the Java 1 00:05.880 --> 00:11.530 developers should invest in learning all the features that got introduced as part of Java8. 2 00:11.970 --> 00:17.580 We all know that Java is one of the most popular and widely accepted language in the world. Since it's 3 00:17.670 --> 00:19.790 already one of the mostly used language. 4 00:19.800 --> 00:26.910 Why the Java creators decided to change it. Java creators decided they wanted to introduce the functional 5 00:26.910 --> 00:34.590 features such as Lambdas, Streams, Optionals and etc because of the technology advancements that are happening 6 00:34.620 --> 00:35.880 around the world. 7 00:35.880 --> 00:41.670 Even a smart mobile in our hands have multiple processors in order to make use of the multiple 8 00:41.670 --> 00:45.520 processors prior to Java 8 you have to use threads. 9 00:45.560 --> 00:51.450 Otherwise you will just be accessing only one processor even though the system that you with you 10 00:51.660 --> 00:57.870 have multiple processors and we all know that working with threads is so touchy and you have to be 11 00:57.870 --> 00:59.620 really really careful working with Threads. 12 00:59.620 --> 01:07.470 With Java8 we will be able to write the functional programming code using the new functional concepts 13 01:07.740 --> 01:14.610 which is going to help you simplify the concurrency operations which will make use of the multiple processors 14 01:14.970 --> 01:18.250 whenever you perform the concurrency operations. 15 01:18.380 --> 01:25.030 We will be covering a lot of examples on this topic in the course. Now, we'll talk about what are the other 16 01:25.030 --> 01:28.540 capabilities that functional programming can help you achieve. 17 01:28.660 --> 01:36.030 It supports creating immutable objects which is going to solve a lot of problems in the java application. 18 01:36.070 --> 01:43.360 If you think about it mutable objects are the source for many errors in java application and functional programming 19 01:43.650 --> 01:51.690 highly discourages mutating an object and functional programming is going to let you write more concise 20 01:51.780 --> 01:55.560 and readable code. With Java8 21 01:55.580 --> 02:01.040 it is going to let you use the functions or methods as first class citizens. 22 02:01.160 --> 02:08.930 What does it mean is that functional programming is going to let you create a function and assign that functionality 23 02:08.960 --> 02:13.580 to a variable and pass it around as like method parameters. 24 02:13.580 --> 02:16.000 This was never possible before Java 8. 25 02:16.040 --> 02:18.650 This is an excellent addition to Java8. 26 02:18.980 --> 02:21.700 Here is a simple example that I have here. 27 02:21.950 --> 02:26.930 This whole line might look new to you because function is something which got introduced as part of 28 02:26.930 --> 02:27.980 Java8. 29 02:28.040 --> 02:32.960 This represents the input and this represents the output and we have a new syntax here. 30 02:32.960 --> 02:35.110 This syntax is called lambda syntax. 31 02:35.270 --> 02:40.380 You don't have to worry about it for now because I'll be walking you through all these concepts step 32 02:40.400 --> 02:44.030 by step and we're going to cover all these concepts via code. 33 02:44.040 --> 02:48.700 Don't worry about it for now. Let me explain what's happening here. 34 02:48.770 --> 02:54.110 So here the input is going to be a string and then we are performing the uppercase operation on it and 35 02:54.110 --> 02:58.790 then followed by that we are performing the concatenation operation here. 36 02:58.880 --> 03:05.360 Basically two operations are happening and this logic is being assigned to a variable called add some 37 03:05.360 --> 03:10.430 string and we can pass this add some string as like any other variable in Java. 38 03:10.490 --> 03:18.050 That's one of the benefits of functional programming. With Java8 it is going to let you write the code 39 03:18.140 --> 03:24.170 in a declarative way rather than an imperative way. What does it mean? I'm going to highlight the difference 40 03:24.170 --> 03:28.180 between imperative and declarative style of programming. 41 03:28.250 --> 03:30.870 Let's talk about the imperative style of programming. 42 03:32.310 --> 03:37.200 This style of programming focuses on how to get the result that we want. 43 03:37.440 --> 03:43.860 This style of programming embrace's changing the object's state to achieve an objective which is nothing 44 03:43.860 --> 03:50.340 but mutating an object and getting that result you want. Lets say you want to achieve an objective then 45 03:50.370 --> 03:54.100 you define the list of steps to achieve an objective. 46 03:54.300 --> 03:58.140 You code what needs to be done in each step. 47 03:58.170 --> 04:04.790 Imperative programming is a concept used behind the classic object oriented programming style. 48 04:05.070 --> 04:07.770 Now let's talk about that declarative programming. 49 04:08.850 --> 04:12.630 This style of programming focuses on what is the result you want. 50 04:12.660 --> 04:16.500 It does not bother or worry about how to get the result. 51 04:16.590 --> 04:23.990 This style of programming embraces object immutability. This style of programming is analogous to SQL. 52 04:24.260 --> 04:24.980 In SQL, 53 04:24.990 --> 04:29.330 we request for data from the tables but we don't care about what is 54 04:29.380 --> 04:33.820 algorithm or how the data is retrieved from the DB. Right ? 55 04:33.950 --> 04:41.180 Declarative style of programming is similar to the same concept. We will make use of the 56 04:41.180 --> 04:43.400 functions that comes with the language. 57 04:43.490 --> 04:45.160 So far Java 8, 58 04:45.290 --> 04:48.570 there are lot of functions that got introduced as part of it. 59 04:48.630 --> 04:53.260 You're going to make use of those functions in order to get the result we want. 60 04:53.270 --> 04:58.550 You don't have to worry about how the data is processed behind the scenes in order to get the result 61 04:58.550 --> 04:59.570 you want. 62 04:59.570 --> 05:06.350 Functional programming uses a concept of declarative programming. I would like to explain the difference between 63 05:06.350 --> 05:10.070 the imperative style and declarative style using some examples. 64 05:10.100 --> 05:11.970 We'll code this in the following tutorials. 65 05:12.190 --> 05:14.320 With we came to the end of the theory part. 66 05:14.510 --> 05:15.480 Thank you for watching.