WEBVTT 00:00.890 --> 00:08.090 JavaScript is a different language from other programming languages like Java, C, Sharp or B, and 00:08.090 --> 00:13.730 the one thing that makes JavaScript even more different from them is prototypic inheritance. 00:14.240 --> 00:16.340 So what is Prototyp inheritance? 00:16.910 --> 00:17.990 Up until this point? 00:18.020 --> 00:20.350 Maybe you have not heard any of these words. 00:20.810 --> 00:25.860 It sounds complicated, but you don't have to worry because I'm going to explain it deeper. 00:26.420 --> 00:31.730 So in JavaScript, every object inherits properties and methods from its prototype. 00:32.300 --> 00:35.690 And actually this relationship is called inheritance. 00:36.560 --> 00:39.010 Prototype itself is an object. 00:39.950 --> 00:47.530 So in other words, objects are linked to other objects and those linked objects are called the prototype. 00:48.530 --> 00:51.800 The prototype is automatically assigned to any object. 00:53.080 --> 00:59.900 OK, as we said, JavaScript is different from other programming languages because of that prototypic 00:59.930 --> 01:00.590 inheritance. 01:01.460 --> 01:06.320 Those languages provide kind of different type of inheritance, which is called classical. 01:07.330 --> 01:14.470 Some of the developers think that prototype inheritance is one of the downsides of JavaScript, but 01:14.470 --> 01:19.240 some of them think opposite, in my opinion, to work with prototype. 01:19.300 --> 01:22.480 Inheritance is much more convenient and flexible. 01:23.650 --> 01:27.160 In case of JavaScript, the engine does automatically. 01:27.160 --> 01:28.320 Lots of work for you. 01:28.810 --> 01:35.890 But for example, in case of classical inheritance, you have to create classes and then organize the 01:35.890 --> 01:37.000 relationship between them. 01:38.230 --> 01:40.960 OK, I'm not going to describe it deeper. 01:41.350 --> 01:46.900 The fact is that you have to do less work in JavaScript when you deal with Prototyp inheritance. 01:48.430 --> 01:48.880 All right. 01:49.270 --> 01:50.740 Without practical examples. 01:50.770 --> 01:53.050 This still sounds complicated. 01:53.530 --> 01:56.440 So let's go back to Brackett's and write some code. 01:58.370 --> 02:03.980 You already know how to create objects, you can use either literal notation. 02:05.160 --> 02:05.580 Or. 02:06.890 --> 02:11.270 Construct a rotation using new operator. 02:12.970 --> 02:19.300 So here we have two empty objects, let's lock them in Castle, White Castle, not like a. 02:22.420 --> 02:24.070 And then consider Lockerby. 02:27.870 --> 02:28.440 Revote. 02:30.030 --> 02:34.800 And I see that we have two empty objects, let's drop down them. 02:36.910 --> 02:44.590 So we have something else you see underscore, underscore Proteau on the score, which is a special 02:44.590 --> 02:51.250 property and points or is linked to object, let's drop down them as well. 02:53.080 --> 02:57.790 You see here a couple of built in methods, and for both objects, they are similar. 02:58.900 --> 03:04.750 So let me explain what's going on here so that we need to know actually what happens behind the scenes 03:05.770 --> 03:13.570 when we create objects using a literal or constructed notations each time we call builtin global object 03:13.570 --> 03:13.990 function. 03:14.990 --> 03:24.770 So if we write in council object, then we will get the motion global object function, I say object 03:24.770 --> 03:26.780 function because its name is object. 03:28.840 --> 03:35.380 This function allows us to create objects, it assigns property to them, which is underscore, underscore, 03:35.420 --> 03:40.720 Proteau, underscore, underscore, and using this property, objects have access on those methods. 03:42.040 --> 03:44.650 So where do all of these methods come from? 03:45.400 --> 03:51.790 In order to find out, we can use prototype property with this global object function and get access 03:51.790 --> 03:52.930 on the machine methods. 03:53.680 --> 03:54.160 That's right. 03:54.170 --> 03:56.050 Object dot prototype. 03:59.190 --> 04:07.200 Let's drop down and you see that we have here exact similar methods as it was in case of Proteau. 04:08.400 --> 04:14.490 So this object and this one are the same in order to prove that. 04:14.640 --> 04:15.260 That's right. 04:15.720 --> 04:18.090 Object dot prototype. 04:19.200 --> 04:20.130 Dot caret. 04:22.520 --> 04:23.720 Equals low. 04:26.780 --> 04:36.950 Reload, as you see here, we have new property, grit, and if we right your object prototype. 04:40.410 --> 04:45.590 Then because of that, those are the same objects we'll get inside it, Garet, as well. 04:47.200 --> 04:53.800 All right, again, when we create objects using literal or constructed notation, automatically we 04:53.800 --> 05:00.760 call global object function, which actually creates those objects and allows them to have link to its 05:00.760 --> 05:01.760 prototype object. 05:03.070 --> 05:03.700 Makes sense. 05:05.220 --> 05:09.790 OK, I know that it's confusing and difficult to understand. 05:09.810 --> 05:17.820 So let me explain once again here we have a built in global object function which has its prototype 05:17.820 --> 05:24.510 object, and it also has access on its prototype object using prototype property. 05:26.000 --> 05:33.440 When we have created objects variable A using literal notation and variable B using constructor notation. 05:34.670 --> 05:40.250 You know that these methods do the same job, but Litoral is more convenient and short on way. 05:41.750 --> 05:48.710 Then both of them invoke object function, which is also a function constructor, and after that it 05:48.710 --> 05:56.410 creates empty objects and assigns to them this underscore, underscore, Proteau underscore, underscore 05:56.410 --> 06:02.130 a property which then allows them to access on the prototype object. 06:03.080 --> 06:09.860 So you see that these newly created objects are the prototype object, which is prototype of global 06:09.860 --> 06:10.820 object function. 06:12.050 --> 06:12.560 All right. 06:13.220 --> 06:14.480 I think it makes sense. 06:14.750 --> 06:19.190 All of those stuff happens behind the scenes when we deal with global object. 06:19.190 --> 06:21.560 Constructor function is the next video. 06:21.560 --> 06:26.680 We'll continue talking about prototypes with manually created function constructors. 06:28.010 --> 06:29.180 See you in the next lecture.