1 00:00:00,780 --> 00:00:07,290 So now you want to actually show you how you can use these protected access modifier. 2 00:00:07,350 --> 00:00:07,790 OK. 3 00:00:07,860 --> 00:00:15,590 But always use the getters and setters in order to access the values of the instance variables. 4 00:00:15,620 --> 00:00:26,190 OK so a name as you can see name and then put into double quotes here color and then I actually put 5 00:00:26,250 --> 00:00:28,060 another plus operator here. 6 00:00:28,110 --> 00:00:32,940 And then again I can actually refer to the name of the color instance variable plus. 7 00:00:33,090 --> 00:00:35,580 And then again I put two double quotes here. 8 00:00:35,580 --> 00:00:37,340 So speed. 9 00:00:38,130 --> 00:00:39,040 OK. 10 00:00:39,510 --> 00:00:41,890 And that puts a plus operator here. 11 00:00:42,060 --> 00:00:43,540 Amount of speed. 12 00:00:44,310 --> 00:00:48,570 And then I put another plus operator here and I put two double quotes here. 13 00:00:49,110 --> 00:00:55,490 Power and then and then I put a plus operator here amount of power. 14 00:00:55,510 --> 00:00:56,760 OK. 15 00:00:57,380 --> 00:01:01,570 As you can see now this is going to actually turn these values. 16 00:01:01,610 --> 00:01:02,310 OK. 17 00:01:02,570 --> 00:01:08,820 So let's actually inside this our main activity that job I find here is instead of just calling these 18 00:01:08,850 --> 00:01:09,960 two string method. 19 00:01:10,220 --> 00:01:12,460 I can't call that out. 20 00:01:12,470 --> 00:01:14,710 Put some values to the screen Nevitt. 21 00:01:14,720 --> 00:01:15,290 OK. 22 00:01:15,470 --> 00:01:18,320 So let's actually run our project and see what happens. 23 00:01:18,320 --> 00:01:22,960 So as you can see here these are the values that are outputted to the screen. 24 00:01:23,000 --> 00:01:24,540 OK name my chat. 25 00:01:24,740 --> 00:01:33,530 So let's actually go inside this Chatz class here as you can see Name Is My chat's color is white and 26 00:01:33,980 --> 00:01:34,680 speed. 27 00:01:34,940 --> 00:01:38,200 As you can see he's 40 and power is 50. 28 00:01:38,270 --> 00:01:38,830 OK. 29 00:01:38,960 --> 00:01:45,220 And let's actually go ahead and actually put our implementation's inside this lower class. 30 00:01:45,230 --> 00:01:46,150 OK. 31 00:01:46,790 --> 00:01:54,480 So now let me actually point out that always allow other classes to access your instance variables by 32 00:01:54,490 --> 00:01:56,800 using the getters and setters. 33 00:01:56,810 --> 00:01:57,460 OK. 34 00:01:57,740 --> 00:02:05,540 So let's actually change these protected access modifiers to privates because in this way our codes 35 00:02:05,600 --> 00:02:06,750 are more secure. 36 00:02:06,820 --> 00:02:07,590 OK. 37 00:02:07,760 --> 00:02:14,120 And we can actually restrict the access to these instance variables by just creating getters and setters 38 00:02:14,750 --> 00:02:19,190 so that other classes can not directly access these private parts. 39 00:02:19,190 --> 00:02:19,820 OK. 40 00:02:19,940 --> 00:02:21,400 So hopefully that makes sense. 41 00:02:21,650 --> 00:02:24,360 And let's go actually inside this lion class. 42 00:02:24,410 --> 00:02:31,700 And as you know the lion is actually part of the it's actually part of the Chadha family animals. 43 00:02:31,700 --> 00:02:32,340 OK. 44 00:02:32,570 --> 00:02:42,970 So we can actually say that a lion is a cat's OK extends Chatz OK. 45 00:02:43,960 --> 00:02:52,270 So as you can see here now our lion class is actually inheriting all of the features and behaviors that 46 00:02:52,270 --> 00:02:54,010 are inside this cat class. 47 00:02:54,010 --> 00:02:54,660 OK. 48 00:02:54,670 --> 00:03:02,360 So here inside this class I can actually create some instance variables that are only special to display 49 00:03:02,360 --> 00:03:02,940 in class. 50 00:03:03,040 --> 00:03:06,190 For example Ilyin is a brave animal. 51 00:03:06,460 --> 00:03:15,440 So I can actually create a boolean variable private boolean is brai OK. 52 00:03:15,710 --> 00:03:16,770 And then I. 53 00:03:16,940 --> 00:03:19,590 And then I put a semicolon at the end of this statement here. 54 00:03:19,610 --> 00:03:20,290 OK. 55 00:03:20,690 --> 00:03:27,890 So now as you can see these are characteristic is only specific to display in class. 56 00:03:27,890 --> 00:03:28,820 OK. 57 00:03:28,850 --> 00:03:33,580 So here I can actually create a constructor for this class. 58 00:03:33,590 --> 00:03:39,260 So first of all I need to actually put the public access modifier here and then I need to actually specify 59 00:03:39,590 --> 00:03:43,610 the name of my constructor for this line class. 60 00:03:43,640 --> 00:03:48,500 So the name of this constructor must be the same as the name of this line class. 61 00:03:48,500 --> 00:03:48,810 OK. 62 00:03:48,820 --> 00:03:49,990 Lion. 63 00:03:50,420 --> 00:03:56,900 And then I put up around brackets after my constructor name and then I open and close my constructor 64 00:03:57,110 --> 00:03:58,870 by using these curly braces. 65 00:03:58,880 --> 00:04:04,020 So inside the prentices as you can see we need to actually specify some arguments. 66 00:04:04,130 --> 00:04:07,070 Otherwise the Android studio is going to actually complain. 67 00:04:07,160 --> 00:04:11,170 Let's actually cover our mouse pointer over this error area. 68 00:04:11,360 --> 00:04:18,650 There is no default constructor available in chat class as you can see that example that Matas I saw 69 00:04:18,650 --> 00:04:20,680 that that app for that chat. 70 00:04:20,840 --> 00:04:28,160 So let's go actually inside this math class as you can see we've got our custom constructor inside this 71 00:04:28,160 --> 00:04:28,780 class. 72 00:04:28,790 --> 00:04:29,100 OK. 73 00:04:29,120 --> 00:04:30,830 There is no default constructor. 74 00:04:30,950 --> 00:04:37,220 So we need to actually initialize the constructor that is inside this class because we are inheriting 75 00:04:38,230 --> 00:04:41,100 the behaviors and features that are inside that class. 76 00:04:41,110 --> 00:04:41,650 OK. 77 00:04:41,950 --> 00:04:49,610 So here I can just typing super And then inside Apprentice's I need to actually pass these values up. 78 00:04:49,630 --> 00:04:51,970 Name Caller amount of speed. 79 00:04:51,970 --> 00:04:57,680 Amount of power or number of legs and can hunt other animals which is a boolean value. 80 00:04:57,690 --> 00:05:04,090 OK so here I can actually specify some arguments for this constructor. 81 00:05:04,290 --> 00:05:04,760 OK. 82 00:05:04,840 --> 00:05:10,960 So that whenever we actually create an object from this lower class we need to pass those values to 83 00:05:10,960 --> 00:05:12,370 the constructor OK. 84 00:05:12,640 --> 00:05:16,060 So the first value is going to be the name. 85 00:05:16,470 --> 00:05:19,870 OK so strange name. 86 00:05:20,140 --> 00:05:27,520 And the second argument is again color and our first argument is of type int and the name of that argument 87 00:05:27,520 --> 00:05:30,840 is amount of speed. 88 00:05:31,140 --> 00:05:40,370 Ok comma in that amount of power comma. 89 00:05:40,780 --> 00:05:47,320 So let's actually go inside this cat class in order to see other values other arguments so name caller 90 00:05:47,920 --> 00:05:48,720 amount of speed. 91 00:05:48,730 --> 00:05:52,260 Amount of power a number of legs can hunt other animals. 92 00:05:52,270 --> 00:05:53,150 OK. 93 00:05:53,540 --> 00:05:58,940 Int number of legs. 94 00:05:59,470 --> 00:06:00,190 OK. 95 00:06:00,430 --> 00:06:05,130 Boullion can haunt other animals. 96 00:06:05,140 --> 00:06:06,040 OK. 97 00:06:09,030 --> 00:06:16,770 So let's actually create a new line here in order to actually see these are arguments better. 98 00:06:16,800 --> 00:06:17,570 OK. 99 00:06:17,970 --> 00:06:21,810 And we have another instance variable which is specific. 100 00:06:21,840 --> 00:06:23,690 Only two these are like in class. 101 00:06:23,700 --> 00:06:24,500 OK. 102 00:06:24,510 --> 00:06:25,520 Is brief. 103 00:06:25,650 --> 00:06:28,750 So boolean is brave. 104 00:06:28,860 --> 00:06:29,360 OK. 105 00:06:29,430 --> 00:06:34,960 So here in say the apprentice's of the superhero I can just pass these values. 106 00:06:34,980 --> 00:06:35,370 OK. 107 00:06:35,400 --> 00:06:47,100 Name comma color comma amount of speed comma and out of power comma. 108 00:06:47,430 --> 00:06:52,910 Number of Lex comma and can hunt other animals. 109 00:06:53,210 --> 00:06:53,980 OK. 110 00:06:54,270 --> 00:06:57,750 So as you can see here these are the arguments. 111 00:06:57,750 --> 00:07:02,950 These are the values that we specified for this chat class. 112 00:07:02,970 --> 00:07:03,540 OK. 113 00:07:03,750 --> 00:07:11,430 As you can see here these are the arguments that we specified for this cat class yet he conceived for 114 00:07:11,430 --> 00:07:16,310 this for the constructor of this Kathe Class VI is specified these arguments. 115 00:07:16,320 --> 00:07:18,730 Ok name caller amount of speed. 116 00:07:18,750 --> 00:07:22,620 Amount of power number of legs and can hunt other animals. 117 00:07:22,830 --> 00:07:28,800 So because this lion class is actually inheriting all of those are features and behaviors that are inside 118 00:07:28,800 --> 00:07:32,790 this cat class into this lion class here. 119 00:07:32,890 --> 00:07:37,480 We need to actually initialize the constructor of the superclass. 120 00:07:37,530 --> 00:07:41,740 OK so this super refers to this chat class here. 121 00:07:41,820 --> 00:07:42,470 OK. 122 00:07:42,810 --> 00:07:48,570 And we need to actually first of all initialize the constructor of this class and then we can actually 123 00:07:48,570 --> 00:07:51,900 initialize our own instance variable here. 124 00:07:51,900 --> 00:08:00,260 So first I just need to type in this in order to refer to this lower class that is brief assignment 125 00:08:00,300 --> 00:08:04,370 operator and here I can I truly referred to this argument here. 126 00:08:04,370 --> 00:08:06,040 OK it is brave. 127 00:08:06,180 --> 00:08:13,350 Now as you can see I initialized my own r instance variable here my own instance variable inside this 128 00:08:13,350 --> 00:08:14,780 line class OK. 129 00:08:15,180 --> 00:08:20,560 And here in this line of code I initialized the constructor of the superclass. 130 00:08:20,750 --> 00:08:26,540 OK so that I don't need to actually redeclare these instance variables inside this class. 131 00:08:26,550 --> 00:08:30,800 So again that's the power of inheritance with just one line of code. 132 00:08:30,940 --> 00:08:36,930 We actually managed to initialize all all of these instance variables OK and we didn't declare these 133 00:08:36,930 --> 00:08:43,170 instance variables and we just inherited all of these instance variables and we can use them. 134 00:08:43,310 --> 00:08:43,900 OK. 135 00:08:44,050 --> 00:08:50,480 And I can actually create a set here and I'll get her Meffert for this is brave instance variable. 136 00:08:50,580 --> 00:08:57,540 Again I'd like to clear out of this constructor here and inside this in class I wrote click here and 137 00:08:57,540 --> 00:09:05,700 then I click on generate and then I click on get her and set her and here choose this is brave instance 138 00:09:05,700 --> 00:09:07,680 variable here and then click on OK. 139 00:09:08,030 --> 00:09:08,730 OK. 140 00:09:09,090 --> 00:09:14,640 So as you can see here this is our Get here for this instance variable is brave. 141 00:09:14,760 --> 00:09:17,940 And this is our set here for this instance variable. 142 00:09:18,180 --> 00:09:20,820 So I don't like this name here is brave. 143 00:09:20,820 --> 00:09:24,140 So let's actually change this number to get brave. 144 00:09:24,150 --> 00:09:25,280 OK. 145 00:09:25,650 --> 00:09:27,370 So hopefully that makes sense. 146 00:09:27,810 --> 00:09:34,500 And now I want to actually override the twisting method that I actually inherit from the Object class. 147 00:09:34,500 --> 00:09:34,990 OK. 148 00:09:35,160 --> 00:09:37,070 So I just need to type in here two was three. 149 00:09:37,110 --> 00:09:40,040 Now we can actually override this method. 150 00:09:40,050 --> 00:09:42,480 So let's actually delete this line of code here. 151 00:09:42,600 --> 00:09:50,250 We can actually inherit the implementations that are inside this Kathe class here. 152 00:09:50,290 --> 00:09:50,770 OK. 153 00:09:50,830 --> 00:09:54,920 As you can see we did actually put this code here. 154 00:09:55,090 --> 00:10:04,200 So now we can actually use this code inside this line class by just typing in return super dot to think.