1 00:00:00,180 --> 00:00:05,620 Hire everyone in this theater you are really going to go ahead and create another Android application. 2 00:00:05,640 --> 00:00:09,520 So just click on this start in your Android studio project here. 3 00:00:09,660 --> 00:00:19,030 And for the application name just type in your app 29 and then click on Next choose API 16 Android 4.1 4 00:00:19,050 --> 00:00:22,020 jelly been for minimum STK click on next. 5 00:00:22,530 --> 00:00:27,280 And then choose Blanc's activity next and then click on finish. 6 00:00:27,300 --> 00:00:28,030 OK. 7 00:00:28,200 --> 00:00:34,350 Now let's actually select these hellova or text view here and then press on delete key on your keyboard 8 00:00:34,890 --> 00:00:38,010 and then double click on this LS folder here. 9 00:00:38,270 --> 00:00:40,380 Lay out activity on the line. 10 00:00:40,380 --> 00:00:41,570 Make that example. 11 00:00:42,030 --> 00:00:47,580 And then here selectees faluting action button here and then press on delete key on your keyboard. 12 00:00:47,580 --> 00:00:52,840 OK so now let's actually go back and say this content underly mean that exemption. 13 00:00:52,860 --> 00:00:57,630 And then here we can actually design the user interface of our application. 14 00:00:57,660 --> 00:00:58,190 OK. 15 00:00:58,260 --> 00:01:04,020 Now let's actually select this linearly elsewheres call here and put it at the center of this relatively 16 00:01:04,020 --> 00:01:04,610 out here. 17 00:01:04,620 --> 00:01:05,320 OK. 18 00:01:05,850 --> 00:01:13,230 And then let's actually select these are vertical scroll view here and put it at the center of this 19 00:01:13,470 --> 00:01:21,270 linearly vertical and then lets actually select is linearly onto a circle and put it inside this scroll 20 00:01:21,270 --> 00:01:21,970 view here. 21 00:01:22,050 --> 00:01:22,850 OK. 22 00:01:23,340 --> 00:01:28,740 And then now let's actually select this large text view and put it inside this linearly Ellsworth's 23 00:01:28,750 --> 00:01:31,840 the call that is inside of this scroll view here. 24 00:01:31,890 --> 00:01:32,730 OK. 25 00:01:33,150 --> 00:01:40,620 And double click on it deletes the text of the stakes and the ID just typing here takes the polymorphism. 26 00:01:40,800 --> 00:01:47,340 And now let's actually go back inside this main activity that are filed here and then let's actually 27 00:01:47,340 --> 00:01:51,830 select these lines of code that are actually related to the Options menu. 28 00:01:52,070 --> 00:01:52,710 OK. 29 00:01:53,130 --> 00:02:00,080 And then select these lines of code that are related to the floating action button and then delete them. 30 00:02:00,090 --> 00:02:03,240 So now we can actually put in our own code here. 31 00:02:03,240 --> 00:02:06,930 Now let's actually create some Java classes in our project. 32 00:02:06,930 --> 00:02:11,730 So just click on File New and then click on Java class. 33 00:02:12,030 --> 00:02:17,950 So for the first class just type in here sport OK and then click on OK. 34 00:02:18,480 --> 00:02:26,630 Let's actually create another class file new Java class and then the name of this class is boxing. 35 00:02:27,830 --> 00:02:29,120 OK. 36 00:02:29,960 --> 00:02:38,190 And let's actually create another class file new double class and the name of this class is kickboxing. 37 00:02:38,810 --> 00:02:41,520 Kick boxing. 38 00:02:42,200 --> 00:02:43,080 OK. 39 00:02:43,760 --> 00:02:51,510 Now let's actually create another job of classified new and Jobbik less. 40 00:02:51,680 --> 00:02:55,200 So for the name of this class is student. 41 00:02:56,200 --> 00:02:57,100 OK. 42 00:02:57,500 --> 00:03:08,900 Now let's actually create an interface new file new Ok Doba class and the name and here for the kind 43 00:03:08,900 --> 00:03:10,590 to choose interface. 44 00:03:10,920 --> 00:03:11,850 OK. 45 00:03:12,380 --> 00:03:16,750 And for the name of this interface just type in here life insurance 46 00:03:20,100 --> 00:03:22,590 OK and then click on OK. 47 00:03:23,300 --> 00:03:31,020 So now I want to talk about interface in Java so interface is actually like your class in Java and it 48 00:03:31,020 --> 00:03:36,170 is actually a reference type interface is actually a clip a collection of abstract methods. 49 00:03:36,180 --> 00:03:36,590 OK. 50 00:03:36,660 --> 00:03:40,200 So we can have a collection of abstract methods in interface. 51 00:03:40,260 --> 00:03:41,230 OK. 52 00:03:41,350 --> 00:03:48,950 And a class that implements an interface for example Maxime's when it wants to implement and in fact 53 00:03:49,050 --> 00:03:54,240 an interface to implements or life insurance as you can see life insurance is actually an interface. 54 00:03:54,240 --> 00:04:02,340 Ok so a class that implements an interface thereby inheriting the abstract methods that are actually 55 00:04:02,370 --> 00:04:04,050 inside of this life insurance. 56 00:04:04,050 --> 00:04:09,930 So as you can see here we don't have any abstract if it's inside of these life insurance interface but 57 00:04:09,930 --> 00:04:15,140 we can have abstract benefits inside of these life insurance interface. 58 00:04:15,150 --> 00:04:15,890 OK. 59 00:04:16,290 --> 00:04:23,760 And along with Misfit's along with abstract methods an interface may also contain constants default 60 00:04:23,790 --> 00:04:27,300 methods and static methods and or nested types. 61 00:04:27,340 --> 00:04:29,500 OK I'll talk more about them later. 62 00:04:29,650 --> 00:04:30,410 OK. 63 00:04:30,630 --> 00:04:37,000 But for now remember that in giove up you can only inherit from one class directly. 64 00:04:37,100 --> 00:04:42,840 OK so in Java we can only inherit all classes can only inherit from one class. 65 00:04:42,900 --> 00:04:43,370 OK. 66 00:04:43,560 --> 00:04:48,560 And they can implement our classes can implement as many interfaces as they want. 67 00:04:48,570 --> 00:04:48,950 OK. 68 00:04:48,990 --> 00:04:54,200 So let's actually create some abstract methods inside of these interface. 69 00:04:54,460 --> 00:04:54,900 OK. 70 00:04:54,960 --> 00:05:02,590 So by default of when we actually create an effect in this interface on if it's actually abstract. 71 00:05:02,750 --> 00:05:10,140 OK so now let's actually create an abstract method inside of these life insurance interface. 72 00:05:10,140 --> 00:05:11,050 So just open here. 73 00:05:11,070 --> 00:05:12,600 Double OK. 74 00:05:13,200 --> 00:05:16,730 And for the name of this abstract method just type in here. 75 00:05:16,900 --> 00:05:19,530 Evaluate OK. 76 00:05:19,600 --> 00:05:25,050 Cost of insurance okay. 77 00:05:25,200 --> 00:05:30,350 And then put a pair of Prentice's here and then put a semicolon at the end of your left. 78 00:05:30,390 --> 00:05:30,940 OK. 79 00:05:31,140 --> 00:05:38,430 So as you know methods in interface cannot have body OK a class that actually implements this interface 80 00:05:38,670 --> 00:05:44,550 must actually provide that body for this interface so as you can see here in say that this box in class 81 00:05:44,910 --> 00:05:48,360 as against this class actually implements this interface. 82 00:05:48,360 --> 00:05:54,630 So we need to actually provide a body to override that Meffert evaluate cost of insurance. 83 00:05:54,870 --> 00:05:59,310 That is actually declared it life insurance interface as you can see. 84 00:05:59,310 --> 00:06:04,050 We need to actually implement that method here inside of this box in class and then provide a body for 85 00:06:04,050 --> 00:06:04,440 that. 86 00:06:04,550 --> 00:06:05,320 OK. 87 00:06:05,910 --> 00:06:09,650 So now first of all let's actually go inside of these sports. 88 00:06:09,660 --> 00:06:15,570 The job of right here and inside of this class is actually putting that letter actually put in some 89 00:06:15,570 --> 00:06:16,850 more lines of code here. 90 00:06:16,980 --> 00:06:17,850 OK. 91 00:06:17,940 --> 00:06:23,240 And first of all let me tell you that this Porth class is actually an abstract class. 92 00:06:23,250 --> 00:06:23,670 OK. 93 00:06:23,760 --> 00:06:26,690 So if I ask you that please give me a sport. 94 00:06:26,830 --> 00:06:28,050 It doesn't make sense. 95 00:06:28,050 --> 00:06:30,670 You may ask what kind of sport do you want. 96 00:06:30,710 --> 00:06:39,780 OK so you mean I said you may want a boxing sport kickboxing sport or actually another kind of sport 97 00:06:39,900 --> 00:06:40,880 for example Judo. 98 00:06:40,990 --> 00:06:44,110 OK sport by itself is actually abstract. 99 00:06:44,160 --> 00:06:50,500 So we need to declare this concept really to actually declare this class as an abstract class. 100 00:06:50,820 --> 00:06:51,850 OK. 101 00:06:52,110 --> 00:06:53,710 So hopefully that makes sense. 102 00:06:53,760 --> 00:06:59,810 So first of all inside of this sport class this actually declared some instance variables here. 103 00:06:59,970 --> 00:07:00,590 OK. 104 00:07:00,900 --> 00:07:05,650 So as you can see here I have an instance variable private string name. 105 00:07:05,820 --> 00:07:06,630 OK. 106 00:07:07,110 --> 00:07:13,860 And I have another instance variable private and the type of this instance variable is strange and the 107 00:07:13,860 --> 00:07:15,980 name of this instance variable is OK. 108 00:07:16,050 --> 00:07:17,720 For example the rules of this sport. 109 00:07:17,730 --> 00:07:18,260 OK. 110 00:07:18,540 --> 00:07:20,430 Private string uniform. 111 00:07:20,910 --> 00:07:25,700 Int speed required ain't Pavarotti's quite yet. 112 00:07:25,720 --> 00:07:32,560 OK so we can actually declare this instance variables as private here. 113 00:07:32,590 --> 00:07:37,610 OK private and I can actually declare this instance variable as private too. 114 00:07:37,860 --> 00:07:43,790 OK so now let's actually create a constructor for this sports class. 115 00:07:43,800 --> 00:07:48,810 So now I'm gonna actually pasting this constructor here and then I'm going to actually explain to you 116 00:07:48,810 --> 00:07:50,190 what's going on here OK. 117 00:07:50,310 --> 00:07:54,320 So as you can see here this is my constructor for this sport class. 118 00:07:54,390 --> 00:07:54,800 OK. 119 00:07:54,900 --> 00:07:59,760 And as you can see public the name of the constructor must be the same as the name of the class. 120 00:07:59,760 --> 00:08:00,370 OK. 121 00:08:00,690 --> 00:08:03,750 And this constructor actually accepts some arguments. 122 00:08:03,750 --> 00:08:04,070 OK. 123 00:08:04,080 --> 00:08:11,200 String name string rules string uniform ain't required in power required. 124 00:08:11,220 --> 00:08:16,380 And as you can see here I am I try to instantiate in my instance variables that I actually declared 125 00:08:16,680 --> 00:08:18,190 inside of this sport class. 126 00:08:18,240 --> 00:08:22,090 So this does name actually refers to this name here. 127 00:08:22,110 --> 00:08:27,760 Assignment operator name the start rules assignments operator rules. 128 00:08:27,780 --> 00:08:32,010 OK so these rules actually refers to these local variable here. 129 00:08:32,070 --> 00:08:37,480 This argument rules the start unifor assignment operator unifor. 130 00:08:37,720 --> 00:08:46,080 OK the start speed required assignments operator speed required does that power required assignment 131 00:08:46,140 --> 00:08:48,110 operator power required. 132 00:08:48,170 --> 00:08:56,400 OK so here let me tell you that a support class this is class actually can implement implements this 133 00:08:56,400 --> 00:08:58,210 life insurance interface ok. 134 00:08:58,350 --> 00:08:59,880 Life insurance. 135 00:09:00,270 --> 00:09:00,870 OK. 136 00:09:01,050 --> 00:09:07,590 So now that we actually specify that this sport class actually implements this life insurance interface 137 00:09:07,920 --> 00:09:15,110 here now we can actually implement the method that is inside of these life insurance class here. 138 00:09:15,120 --> 00:09:15,600 OK. 139 00:09:15,620 --> 00:09:17,920 This evaluate cost of insurance. 140 00:09:17,970 --> 00:09:23,490 So let's let's actually go back and say the spikes in much of a fight here and then it's actually delete 141 00:09:23,550 --> 00:09:25,050 this piece of quote here. 142 00:09:25,140 --> 00:09:26,140 OK. 143 00:09:26,760 --> 00:09:34,260 And now let's actually go back inside this sports class as you can see here because our class is an 144 00:09:34,320 --> 00:09:35,490 abstract class. 145 00:09:35,550 --> 00:09:36,150 OK. 146 00:09:36,390 --> 00:09:41,820 And here we are actually implementing this life into a life insurance interface. 147 00:09:42,270 --> 00:09:45,420 We can actually or the compiler doesn't show us any error. 148 00:09:45,480 --> 00:09:51,540 Ok but if this class wasn't an abstract class let's actually delete this abstract keyword here. 149 00:09:51,570 --> 00:09:57,540 Now as you can see the compiler is actually showing us an error and it says class support must either 150 00:09:57,540 --> 00:10:03,710 be absolute must be either be declared abstract or implement abstract method. 151 00:10:03,750 --> 00:10:07,770 Evaluate cost of insurance in life insurance interface. 152 00:10:07,910 --> 00:10:08,170 Ok.