WEBVTT 00:00.620 --> 00:07.130 Let's actually think of our project that we have another class that is derived from the animal class. 00:07.160 --> 00:15.200 For instance, Cat, we are going to make a function that will invoke the get name and make some the 00:15.200 --> 00:18.440 methods for both dog and cat instances. 00:18.440 --> 00:21.680 So in this case, we're going to also add the cat here. 00:22.940 --> 00:28.760 And without creating the two separate functions, we can use the templates which we're going to start 00:28.760 --> 00:30.570 it doing it now. 00:30.590 --> 00:33.620 My name is Stefan and let's get started our lecture. 00:45.660 --> 00:50.760 So we firstly are going to create, as you can see, this is a protected. 00:50.790 --> 00:54.240 Now we have a public constructors. 00:56.320 --> 00:59.830 After that, we have the dog public animal class. 01:01.360 --> 01:08.230 And we will also create a cat public animal, as we said in previous lecture and uh, earlier of this 01:08.230 --> 01:08.770 lecture. 01:08.770 --> 01:16.660 So here we're going to create a class class cat and it's going to be public animal. 01:18.060 --> 01:22.860 Which is going to be a public public format here. 01:23.250 --> 01:31.310 So inside it, we're going to forward the constructor arguments from cat or from animal to the cat here. 01:31.320 --> 01:35.040 So public the. 01:36.400 --> 01:37.210 Here. 01:38.810 --> 01:47.480 A cat is going to be string name and the animal is going to be name here. 01:49.450 --> 01:52.300 And after that, we're going to add here. 01:53.550 --> 02:00.400 So now we're going to copy assignment operator overloading as we did here in Doc here. 02:00.420 --> 02:04.680 Void operator And let's actually, we will do it like that. 02:04.710 --> 02:15.150 The void operator here, the const cat instead of doc we're going to write it Cat here and Operator 02:15.180 --> 02:16.710 D here. 02:16.710 --> 02:24.360 And the my name is going to be d.my name here. 02:25.640 --> 02:29.350 So now we also need to implement interface. 02:29.360 --> 02:33.410 So the interface is going to be like the void. 02:33.440 --> 02:35.580 No, the interface is going to be a string. 02:35.600 --> 02:38.660 Of course it's going to be the make sound here. 02:38.660 --> 02:41.590 Make sound over it, over. 02:41.590 --> 02:50.000 Read and return The of course, Cat is not saying woof, woof here. 02:50.000 --> 02:51.720 Instead, it's like saying something. 02:51.740 --> 02:53.120 Mew Mew here. 02:53.120 --> 02:55.280 So here. 02:55.280 --> 02:58.160 This mew mew. 03:02.160 --> 03:02.670 Here. 03:02.670 --> 03:07.200 So now it's going to be we are getting to the template parts here. 03:07.440 --> 03:10.380 So after that, we will create a template. 03:12.600 --> 03:15.270 Template Typename. 03:15.270 --> 03:16.110 Name T. 03:19.440 --> 03:20.670 And after that. 03:22.690 --> 03:25.200 We will create something like that. 03:25.280 --> 03:30.280 The function that will get name and make sound. 03:30.850 --> 03:31.810 So. 03:33.170 --> 03:34.400 The void here. 03:35.410 --> 03:41.230 Boyd get name and make sound here. 03:41.500 --> 03:45.790 The key here is the animal. 03:49.490 --> 03:52.250 And see out here. 03:52.340 --> 03:58.820 Now, we need to also add braces here so see out the animal dot getName. 03:59.580 --> 04:00.800 getName. 04:02.940 --> 04:04.470 And that's going to be. 04:05.920 --> 04:13.960 Go here and see out the animal that make sound. 04:14.050 --> 04:20.500 It's going to be in line here because we're going to need the new line after that and after that. 04:20.500 --> 04:26.140 We, as you can see in this main here, we will also need to add cat. 04:26.170 --> 04:29.350 So cat, cat here. 04:31.280 --> 04:35.960 The cat is going to be, for example, the regular cat. 04:35.990 --> 04:39.050 Yeah, regular cat. 04:39.500 --> 04:47.240 And we will use the get name and make son, which is going to pass the cat here like this. 04:48.200 --> 04:49.220 Now we're after that. 04:49.220 --> 04:51.830 We have the return and. 04:52.730 --> 04:53.330 Here. 04:53.330 --> 04:54.380 We have done our code. 04:54.410 --> 05:04.340 So in this code, we can see that we can pass both the dog and cat data types to the get name and make 05:04.340 --> 05:05.390 some function. 05:05.390 --> 05:08.960 Since we have defined the type name here. 05:08.990 --> 05:16.730 Type name template type name is t here before the function definition. 05:16.970 --> 05:23.000 So the type name is a keyword in c plus plus which use the write template. 05:24.180 --> 05:31.350 So the keyword is used for specifying that a symbol in a template definition or declaration is a type. 05:31.350 --> 05:34.740 So in this example, the symbol here is T. 05:35.280 --> 05:41.400 As a result, the function becomes generic and can accept various data types. 05:41.400 --> 05:45.630 And if we build and run this code, we will see something like this. 05:45.630 --> 05:51.150 Here is the G++ Main.cpp. 05:52.630 --> 05:55.920 And adding.here. 05:55.960 --> 05:58.180 Oops, we had a problem with it. 05:58.450 --> 05:59.230 Yeah. 05:59.740 --> 06:02.070 Output here we need to output. 06:02.080 --> 06:02.500 Yeah. 06:02.980 --> 06:06.730 And let's actually run adding cat dot x. 06:06.970 --> 06:10.030 And as you can see here, terrier is barking. 06:10.030 --> 06:10.560 Woof, woof. 06:10.600 --> 06:11.710 Terrier is barking. 06:11.710 --> 06:12.220 Woof, woof. 06:12.220 --> 06:14.890 And regular cat goes mew Mew here. 06:15.400 --> 06:18.560 So you will see something like that. 06:18.580 --> 06:25.720 So please, please ensure that the data type we pass to the generic function has the ability to do all 06:25.720 --> 06:28.100 the operation invoking from the generic function. 06:28.120 --> 06:35.950 However, the compiler will compile if the data type was we pass does not have the except operation. 06:35.950 --> 06:44.080 So in this function template example we need to pass a data type that is an instance of the animal class 06:44.080 --> 06:49.600 so we can pass either instance of the animal class or an instance of a derived class of the animal class 06:49.600 --> 06:50.050 here.