WEBVTT 00:01.190 --> 00:05.840 So we have come to the point where you will introduce to one of the biggest additions in year six, 00:05.840 --> 00:11.480 which is closest, if you are familiar with other object oriented programming languages, then classes 00:11.480 --> 00:12.440 won't be new for you. 00:12.920 --> 00:17.030 But in ethics, classes are not like classes in other object oriented programming. 00:17.030 --> 00:23.390 Languages like Java, C, Sharp, PHP and many others in JavaScript classes are just syntactic sugar 00:23.390 --> 00:25.310 and they make our job much easier. 00:26.150 --> 00:31.790 Actually, classes like Function Constructors, which we have already learned in this lecture, I'm 00:31.790 --> 00:39.650 going to compare it five to six and therefore let's recall how function constructors work, create function. 00:40.850 --> 00:41.480 Person. 00:41.630 --> 00:42.560 Yes, five. 00:44.200 --> 00:50.590 With some parameters, right, first name, that last name. 00:52.400 --> 00:53.200 And H. 00:55.580 --> 00:59.630 As you remember, we need to right then restart first name. 01:01.430 --> 01:03.470 Equals to first name. 01:05.640 --> 01:13.670 Then they stopped last name, it was the last name and do the same for age, right? 01:13.710 --> 01:16.200 Is that H equals to H. 01:18.630 --> 01:24.600 Now, using this construction function, I'm going to create a brand new object using new operator, 01:24.780 --> 01:27.630 right, constant Niek yes, five. 01:29.570 --> 01:40.010 Equals the new person is five and then in search of your arguments as a first name, right, Nick Dan 01:40.880 --> 01:44.630 Smith and as The Age, right, 28. 01:45.930 --> 01:49.280 OK, let's consider what this object looks like right now. 01:49.430 --> 01:50.270 It's five. 01:52.280 --> 01:59.840 So here we have person object with properties and with relevant values, also we have here underscore, 01:59.840 --> 02:05.540 underscore, Proteau, underscore, underscore, which as you remember, is assigned by a function constructor 02:05.540 --> 02:07.760 in order to get access and prototype object. 02:08.720 --> 02:13.820 And also you see here another underscore, underscore, Proteau, underscore, underscore, which actually 02:13.820 --> 02:17.210 allows us to get access on global object function prototype. 02:18.270 --> 02:23.940 Because of that, we have access on prototype object of function constructor, we can assign to it the 02:23.940 --> 02:27.490 method which can be used for every brand new object. 02:28.530 --> 02:31.140 So that's the right person. 02:31.140 --> 02:35.040 S5 five DOT prototype dot. 02:35.610 --> 02:41.700 And right here, the method name about person then assigned to it, anonymous function. 02:44.430 --> 02:45.960 And running council. 02:47.700 --> 02:48.960 The following text. 02:51.140 --> 02:55.190 My name is then insert here. 02:56.310 --> 02:57.570 These dot first name. 03:00.030 --> 03:01.920 Then there's the last name. 03:03.830 --> 03:07.550 And I am an insert here, these dot age. 03:10.130 --> 03:11.150 Years old. 03:12.280 --> 03:16.600 All right, let's call this method for person Niek, it's five. 03:20.870 --> 03:26.480 Reload and we have my name is Nick Smith and I am 28 years old. 03:27.650 --> 03:28.100 All right. 03:28.220 --> 03:32.180 That's the way how we deal with function constructors and prototypes in years five. 03:32.840 --> 03:34.730 Now, let's see what happens in six. 03:35.750 --> 03:39.310 So to read the same stuff, we need to use class keyword. 03:39.830 --> 03:42.170 But before that, let's make here a powder. 03:45.990 --> 03:53.010 And then right klus, which is followed by the name of the class that's right here, person Yes, six. 03:54.750 --> 03:59.130 So actually using different syntax, we have created a function constructor. 03:59.550 --> 04:04.360 And to prove that, let's check the type of class right consultor blog. 04:05.390 --> 04:09.930 You see your type of operator and that person is six. 04:13.280 --> 04:17.210 Reload, and he said that it's a function. 04:17.990 --> 04:24.560 All right, the next thing that we have to do is to use constructor methods in order to assign properties 04:24.560 --> 04:25.870 to the brand new object. 04:26.150 --> 04:26.410 So. 04:26.420 --> 04:26.780 Right. 04:27.260 --> 04:28.580 Keyword constructor. 04:31.510 --> 04:37.240 And here we need to place the parameters, so let's copy them and. 04:39.150 --> 04:39.930 Paste here. 04:45.740 --> 04:51.870 And now it's time to create a brand new object, so write consent, Nick. 04:52.020 --> 04:52.940 Yes, six. 04:55.610 --> 04:56.720 Equals two new. 04:57.780 --> 04:59.010 Person is six. 05:01.800 --> 05:05.610 And then place your arguments right, Nick, as first name. 05:07.180 --> 05:11.980 Then again, Smith and as the age right 28. 05:13.910 --> 05:16.620 Let's check in cons. this object, right, Nic? 05:16.670 --> 05:17.570 Yes, six. 05:20.640 --> 05:28.050 So here we have person ESX object with properties and values, so this person looks like in the exact 05:28.050 --> 05:31.140 same way as it was in case of person is five. 05:32.070 --> 05:32.670 That's right. 05:33.160 --> 05:34.020 Yes, five. 05:35.910 --> 05:39.690 If we drop down, it's you will find that those two objects are almost similar. 05:40.170 --> 05:46.550 The only distinction is that in prototype object of personal use five, we have a method about person. 05:48.000 --> 05:54.210 So to achieve the same in ethics classes is much more easier because we can do it without writing any 05:54.210 --> 05:54.950 prototypes. 05:55.740 --> 05:57.240 So let's see how we can do that. 05:57.460 --> 06:02.460 The first thing to note is that after a constructor method, we don't need to place your Colma. 06:02.820 --> 06:04.590 We can directly create method. 06:05.430 --> 06:06.810 Let's call it about person. 06:08.780 --> 06:10.990 Then grew up from person. 06:11.180 --> 06:14.570 Five, this content and. 06:16.630 --> 06:17.380 Paste here. 06:20.470 --> 06:26.770 Let's call this method for ethics, right, ethics, thought about personal. 06:29.760 --> 06:32.510 Reload and we have the same results. 06:33.550 --> 06:38.740 So actually, we have achieved the exact same, but as you see, in much more easier and convenient 06:38.740 --> 06:38.980 way. 06:39.730 --> 06:43.650 All right, let's move on and talk about prototypic inheritance. 06:44.320 --> 06:46.780 I'm going to create another function constructor. 06:47.910 --> 06:49.870 Let's call it developer. 06:49.920 --> 06:50.730 Yes, five. 06:54.040 --> 07:04.630 And insert here parameters like first name, last name, then, right H. 07:05.920 --> 07:06.820 Experience. 07:09.590 --> 07:12.290 And the last one right here, projects. 07:14.730 --> 07:21.600 As you see, both function constructor's, have first name, last name and age parameters for those 07:21.600 --> 07:22.530 three parameters. 07:22.560 --> 07:25.520 I'm going to use personally as five constructor function. 07:26.220 --> 07:28.830 So we need to write personally as five. 07:30.340 --> 07:37.260 In order to receive developer s five constructor function properties of person is five constructor, 07:37.810 --> 07:41.940 we need to call personalness five and use the special variable. 07:42.030 --> 07:42.430 This. 07:44.720 --> 07:51.200 And also insert your first name, last name and age. 07:53.800 --> 08:02.350 So here, this variable points to brand new object, which will be created using developer, yes, five 08:02.350 --> 08:06.090 constructor function, that's for experience and project parameters. 08:06.100 --> 08:19.040 Let's write this thought experience equals to experience and that these DOT projects equals two projects. 08:19.870 --> 08:20.410 All right. 08:21.010 --> 08:31.140 Now let's create a new object right concept and call it Alex WDEF, then write a new developer. 08:31.570 --> 08:32.320 Yes, five. 08:32.560 --> 08:43.630 And as arguments that place you as the first name Alex, then Brown as last name, then the right authority 08:43.780 --> 08:50.790 as age 10 as experience and write the last one five as projects. 08:52.840 --> 08:54.250 OK, let's say in Castle. 08:55.420 --> 08:56.530 Right, Alex Dev. 08:58.610 --> 09:02.870 So you see that this object contains all the properties and values, as we expected. 09:03.710 --> 09:09.430 OK, let's say that we want to use about person method for newly created developer objects. 09:10.670 --> 09:12.290 For that, we have to do the following. 09:12.290 --> 09:20.060 We have to assign to prototype object of developer S5 construct to the copy of person as five prototype 09:20.060 --> 09:20.510 objects. 09:21.050 --> 09:23.940 And for that we need to use object and create method. 09:24.530 --> 09:26.750 So right developer iOS five. 09:27.590 --> 09:32.360 That prototype equals to objects that create. 09:35.330 --> 09:41.720 And inside parentheses, insert person is five dot prototype. 09:42.800 --> 09:50.240 So again, object to create method is used here because we need to create copy of person s five prototype 09:50.240 --> 09:50.690 object. 09:51.290 --> 09:54.890 And not only the reference to it makes sense. 09:55.820 --> 10:03.020 OK, so now we are able to use about person method from person use five prototype object and use it 10:03.020 --> 10:04.300 for developer object. 10:04.790 --> 10:06.530 So that's right Alex. 10:06.530 --> 10:12.170 That not about person reload. 10:13.260 --> 10:17.090 And we have my name is Alex Brown and I am 30 years old. 10:17.930 --> 10:23.780 So as you see Alex, that object has inherited matter from person is five prototype object. 10:25.080 --> 10:25.570 All right. 10:26.330 --> 10:31.700 Now I'm going to assign a new method to developer is five prototype object, which actually will be 10:31.700 --> 10:36.370 used only for brand new objects created by developer S5 constructor. 10:37.310 --> 10:38.300 So that's right. 10:38.570 --> 10:44.090 Developer S5 dot prototype that about that. 10:45.940 --> 10:48.190 And assigned to it function. 10:51.150 --> 10:56.330 Then write that log and that's yours. 10:56.380 --> 11:02.190 Here are the properties which we have assigned to developer s S5 constructor, so write the following. 11:02.730 --> 11:06.720 My name is then they start first name. 11:09.080 --> 11:17.990 Then use your last name, so right, this dot last name, then I am at this thought age. 11:22.100 --> 11:23.510 Years old, with 11:26.540 --> 11:28.130 and use your experience. 11:31.850 --> 11:44.670 Then, right, the tax, again, years of experience and I have participated in and right here, these 11:44.690 --> 11:45.500 DOT projects. 11:48.460 --> 11:49.510 And then projects. 11:51.910 --> 11:54.090 OK, let's call this method right? 11:57.210 --> 12:03.500 I look, staff thought about that, so if we reload, we will get. 12:04.570 --> 12:12.070 My name is Alex Brown, 30 years old, with 10 years of experience and I have participated in five projects. 12:12.610 --> 12:13.050 All right. 12:13.060 --> 12:17.470 So as we said, this method works only for objects which are created using developer. 12:17.740 --> 12:19.050 Yes, five constructor. 12:19.510 --> 12:24.280 And in order to prove that, let's call this method for Nexus five object as well. 12:24.730 --> 12:25.120 Right. 12:25.120 --> 12:29.260 Nikias five dots about def. 12:32.430 --> 12:40.530 Reload and see that we have an error, which tells us that about that is not a function in order to 12:40.530 --> 12:47.450 understand better why we have used objects that create method, let's get rid of it and leave only person 12:47.450 --> 12:49.050 who is five, that prototype object. 12:50.220 --> 12:57.750 Let's reload and you see that it works now for both objects, the only thing is that we have here undefined 12:57.750 --> 13:01.350 for experience and projects because actually person is five. 13:01.350 --> 13:03.570 Constructor doesn't have those parameters. 13:04.080 --> 13:04.610 All right. 13:05.250 --> 13:09.150 So, again, in this case, both constructors have the same prototype object. 13:09.750 --> 13:17.760 But when we use objects that create new copy of prototype object is created generally in S5, we always 13:17.760 --> 13:21.420 use objects to create a method for more privacy. 13:22.760 --> 13:28.550 OK, I believe you agree that in year five, there are lots of stuff to do regarding Prototyp inheritance, 13:29.150 --> 13:30.320 it's hard to understand. 13:30.320 --> 13:34.400 Also, it causes confusion if you are not an experienced JavaScript developer. 13:34.790 --> 13:38.670 But in case of Essex version, everything becomes much more simpler. 13:39.110 --> 13:44.690 Let's create another class for developer called developer execs. 13:45.920 --> 13:52.070 So in order to inherit from a person who has six properties and methods, we need to use keyword extents. 13:54.250 --> 13:56.290 And that person is six. 13:59.610 --> 14:05.820 Now, again, we have to use constructor method with all the parameters, so right here, constructor 14:07.080 --> 14:11.190 and then copy the parameters. 14:15.190 --> 14:23.110 Let's take a look on S5 version, so here we have used called Method, and I believe you have understood 14:23.110 --> 14:24.010 why we have done it. 14:24.820 --> 14:31.090 But in Essex, it's no longer needed because there exists a built in method called Super, which actually 14:31.090 --> 14:33.310 will call for an ethics class. 14:33.820 --> 14:40.810 So in this case, remember, that person is 6th class is called as super class and developer. 14:40.820 --> 14:43.540 Ethics class is called as subclass. 14:44.560 --> 14:57.340 All right, let's use super method and insert as arguments, first name, last name and age. 14:58.360 --> 15:05.320 And then for the rest of the parameters, I mean, experience and projects, we have to write this thought 15:05.320 --> 15:06.250 experience. 15:07.480 --> 15:11.980 Equals the experience and then they start projects. 15:14.300 --> 15:21.160 Equals two projects, besides that, we have about about 12 methods, so that's created 15:23.570 --> 15:27.080 and then copy the content 15:31.010 --> 15:31.970 and paste here. 15:33.230 --> 15:35.340 All right, everything is ready. 15:35.990 --> 15:37.580 I'm going to create a new object. 15:37.970 --> 15:48.920 Let's call it Bob Deve, which equals the new developer ethics and insert here arguments. 15:48.920 --> 15:52.130 Bob, as first name that James. 15:53.810 --> 16:05.940 That 40, 15 and for example, seven and then call about their method, right, Bob Taft thought about 16:05.940 --> 16:06.290 death. 16:10.060 --> 16:19.120 Reload and we have my name is Bob James, 40 years old, with 15 years of experience and I have participated 16:19.120 --> 16:20.590 in seven projects. 16:21.250 --> 16:25.600 All right, let's try to use about person method for bulked up object. 16:26.770 --> 16:27.090 Right. 16:27.100 --> 16:28.630 Bob Taft, what about person? 16:32.010 --> 16:35.590 Reload and see that it works perfectly as well. 16:36.300 --> 16:40.980 But if we try to use about that method for Nick, it's six object, 16:47.500 --> 16:48.930 then we will get an error. 16:49.620 --> 16:57.030 And I'm sure you guessed why when we use six behind the scenes happens the same stuff that was in case 16:57.030 --> 16:58.290 of using object. 16:58.300 --> 17:01.150 That great method makes sense. 17:01.470 --> 17:07.380 OK, I know that it was a bit hard lecture, but I try to show you clearly the difference between five 17:07.380 --> 17:14.010 and six when we deal with the type of inheritance, I hope you undecidable everything, but if not, 17:14.010 --> 17:16.110 you can watch the video carefully. 17:17.160 --> 17:18.810 All right, let's go ahead.