1 00:00:00,780 --> 00:00:08,600 So for example our this is our Get Real Meffert for for my Chan hunt other animals are instance valuable. 2 00:00:08,610 --> 00:00:09,100 OK. 3 00:00:09,240 --> 00:00:10,720 Can hunt other animals. 4 00:00:10,830 --> 00:00:13,330 I don't like this name so I just did it. 5 00:00:13,350 --> 00:00:14,530 This is here. 6 00:00:14,700 --> 00:00:17,860 And I just type in get can hunt other animals. 7 00:00:17,880 --> 00:00:18,510 OK. 8 00:00:18,840 --> 00:00:26,910 So as you can see here we've got acetyl my favorite for this can hunt other animals said can hunt other 9 00:00:26,910 --> 00:00:27,780 animals. 10 00:00:28,010 --> 00:00:28,720 OK. 11 00:00:29,130 --> 00:00:32,090 We've got a good term effort for this. 12 00:00:32,100 --> 00:00:35,480 Get a number of legs for instance variable here. 13 00:00:35,490 --> 00:00:39,900 This is the number of legs instance variable as you can see this is a constant. 14 00:00:39,900 --> 00:00:40,410 OK. 15 00:00:40,470 --> 00:00:47,060 So we cannot actually change the value of this instance valuable from another MFL or class. 16 00:00:47,130 --> 00:00:55,080 Once we give a value to this instance valuable OK so we only can actually create a getter method for 17 00:00:55,090 --> 00:00:58,080 this number of instance variable. 18 00:00:58,090 --> 00:00:59,690 OK because this is a constant. 19 00:00:59,850 --> 00:01:05,700 So as you can see here the Android studio only generated a get fit for this number of likes instance 20 00:01:05,700 --> 00:01:06,450 variable. 21 00:01:06,510 --> 00:01:09,080 We don't have any search term for this. 22 00:01:09,110 --> 00:01:13,500 A number of instance variable OK this is only our Get help method. 23 00:01:13,590 --> 00:01:18,580 OK publish and get a number of leks returnable Oblak number of links. 24 00:01:18,750 --> 00:01:26,910 And here we have this gets amount of power methhead as you can see this is a good fit for the amount 25 00:01:26,910 --> 00:01:28,790 of power instance variable. 26 00:01:29,000 --> 00:01:29,810 OK. 27 00:01:30,270 --> 00:01:34,220 And this is a settlement worth for the amount of power instance variable. 28 00:01:34,260 --> 00:01:39,120 This is our Get and my faith for the for the amount of speed instance variable. 29 00:01:39,360 --> 00:01:44,510 And this is a set in my faith for the amount of spit instance variable and we've got these two getter 30 00:01:44,520 --> 00:01:51,100 methods for the color instance variable and for the name instance variable as you can see here these 31 00:01:51,100 --> 00:01:53,490 two instance variables are constants. 32 00:01:53,550 --> 00:01:54,220 Okay. 33 00:01:54,540 --> 00:02:00,180 So as you can see here we cannot change the value of these two instance variables from another method 34 00:02:00,450 --> 00:02:01,260 or class. 35 00:02:01,260 --> 00:02:04,700 Once we give a value to these instance variables. 36 00:02:04,770 --> 00:02:11,260 So the Android studio only generated a getter method for these instance variables here. 37 00:02:11,270 --> 00:02:12,020 OK. 38 00:02:12,480 --> 00:02:13,800 Get caller get name. 39 00:02:13,830 --> 00:02:17,310 OK we don't have a certain method for these instance variables here. 40 00:02:17,310 --> 00:02:17,660 OK. 41 00:02:17,740 --> 00:02:24,660 We cannot create a certain method for this instance variables because we declared these instance variables 42 00:02:25,170 --> 00:02:26,410 as constant. 43 00:02:26,510 --> 00:02:27,110 OK. 44 00:02:27,360 --> 00:02:28,980 So hopefully that makes sense. 45 00:02:29,250 --> 00:02:36,840 And let's actually go inside the main activity that Java here and now I want to actually output some 46 00:02:36,840 --> 00:02:38,300 text to the screen. 47 00:02:38,340 --> 00:02:38,940 OK. 48 00:02:39,420 --> 00:02:44,800 So here I just need to create an object from the cat class. 49 00:02:44,820 --> 00:02:51,420 So first of all I just need to refer to the name of the class and the name of my object is Chatz one. 50 00:02:51,870 --> 00:03:01,600 And then I put an assignment operator here and then I actually put this key word here Neal chat's as 51 00:03:01,600 --> 00:03:04,820 you can see here and it inside the here. 52 00:03:04,960 --> 00:03:07,990 I need to actually passing some values as you can see here. 53 00:03:07,990 --> 00:03:10,320 String name string color. 54 00:03:10,470 --> 00:03:13,120 I'm out of speed in amount of power. 55 00:03:13,120 --> 00:03:17,280 Number of legs and this boolean variable can hunt other animals. 56 00:03:17,290 --> 00:03:17,950 OK. 57 00:03:18,140 --> 00:03:25,660 So we actually create on an object for the chad class the constructor of these class is going to be 58 00:03:25,660 --> 00:03:26,070 called. 59 00:03:26,080 --> 00:03:27,730 OK so this is the constructor. 60 00:03:27,820 --> 00:03:30,430 So we need to actually pass those values here. 61 00:03:30,550 --> 00:03:32,270 Here inside Apprentice's. 62 00:03:32,290 --> 00:03:32,800 OK. 63 00:03:32,950 --> 00:03:37,580 So first of all I need to actually pass a value of type string. 64 00:03:37,780 --> 00:03:42,480 As you can see here inside the cathe class the first argument is of types 3 and. 65 00:03:42,590 --> 00:03:44,360 And the name of this argument is name. 66 00:03:44,410 --> 00:03:47,470 So we need to actually give a name to this chat object. 67 00:03:47,620 --> 00:03:52,050 So I just need to put in two double calls here and then inside the table Cotes. 68 00:03:52,150 --> 00:03:54,880 I can't actually just type in a name. 69 00:03:54,880 --> 00:04:07,270 For example my chat the name of my cat is cat object is my cat comma and the value for the second argument 70 00:04:07,270 --> 00:04:16,250 must be again as three in value as you can see inside the class the data type of this argument is our 71 00:04:16,400 --> 00:04:19,370 strength and the name of this argument is color. 72 00:04:19,390 --> 00:04:22,170 So we need to actually specify the color of an object. 73 00:04:22,210 --> 00:04:25,020 So let's go back and say the main activity that Java here. 74 00:04:25,150 --> 00:04:33,640 I just need to put into double quotes and for example the color of my cat is white and then I put a 75 00:04:33,640 --> 00:04:38,710 comma here and then I need to actually specify my first argument here. 76 00:04:38,770 --> 00:04:41,960 So let's go back inside the cat the java file. 77 00:04:42,010 --> 00:04:48,980 As you can see my first argument is of type integer and the name of my argument is amount of speed. 78 00:04:49,060 --> 00:04:52,080 So we need to actually pass a value of like integer. 79 00:04:52,090 --> 00:04:56,390 So for example the speed of my chat is 40. 80 00:04:56,710 --> 00:04:57,210 OK. 81 00:04:57,280 --> 00:04:59,710 And then I need to actually put a comma here. 82 00:04:59,980 --> 00:05:05,920 So here I need to actually specify the fourth argument for my constructor here. 83 00:05:05,980 --> 00:05:11,490 So let's go back and say the cat the java file as you can see our forth argument is of type integer 84 00:05:11,800 --> 00:05:13,470 and the name of my argument is. 85 00:05:13,460 --> 00:05:14,590 Amount of power. 86 00:05:14,650 --> 00:05:18,830 So I need to specify the amount of power of my cat object. 87 00:05:18,850 --> 00:05:22,030 For example 40 karma. 88 00:05:22,420 --> 00:05:25,550 And here we need to actually specify the fefe argument. 89 00:05:25,690 --> 00:05:30,790 So let's go back and say they kept the chatter of a fight here and we need to actually specify the number 90 00:05:30,790 --> 00:05:33,310 of legs for our chat object. 91 00:05:33,310 --> 00:05:37,870 The number of legs of my cat object is four comma. 92 00:05:38,500 --> 00:05:41,950 And let's actually go back in say the cat fight again. 93 00:05:42,100 --> 00:05:44,910 And here we need to actually specify our last argument. 94 00:05:44,920 --> 00:05:45,560 OK. 95 00:05:45,730 --> 00:05:51,670 Which is of type Boolean and the name of our argument is can hunt other animals. 96 00:05:51,730 --> 00:05:59,050 So let's go back and say the main activity that over here for example troll or cat object can hunt other 97 00:05:59,260 --> 00:05:59,740 animals. 98 00:05:59,740 --> 00:06:00,090 OK. 99 00:06:00,100 --> 00:06:04,130 As you can see here I want to actually output these values to the screen. 100 00:06:04,210 --> 00:06:07,300 So let's go back inside to catch up the job fight here. 101 00:06:07,330 --> 00:06:15,430 As you can see here we didn't actually overwrite the two strange Mefford that that is inside the Object 102 00:06:15,430 --> 00:06:15,750 class. 103 00:06:15,780 --> 00:06:22,640 OK so as you can see here this cat class implicitly inherits from the Object class. 104 00:06:22,660 --> 00:06:23,220 OK. 105 00:06:23,470 --> 00:06:30,520 So if you want to actually explicitly say that this cathe class inherits from the Object class I just 106 00:06:30,520 --> 00:06:34,240 need to type in here extents object. 107 00:06:34,260 --> 00:06:42,520 OK but if we don't put these two words here are Kathe class is going to implicitly inherit from the 108 00:06:42,610 --> 00:06:43,320 Object class. 109 00:06:43,330 --> 00:06:43,660 OK. 110 00:06:43,660 --> 00:06:50,710 This cat class inherits all of the features and behaviors that are inside the Object class. 111 00:06:50,830 --> 00:06:56,470 So inside the main activity that Java here if you want to actually call that to string method let's 112 00:06:56,470 --> 00:06:57,340 see what happens. 113 00:06:57,340 --> 00:07:05,910 T XTi chat that said text chat's one dot to. 114 00:07:06,940 --> 00:07:10,010 As you can see here inside the Chatta class. 115 00:07:10,120 --> 00:07:10,690 We didn't. 116 00:07:10,720 --> 00:07:11,730 All right. 117 00:07:11,740 --> 00:07:13,190 That was Thring method here. 118 00:07:13,210 --> 00:07:13,900 OK. 119 00:07:13,900 --> 00:07:19,130 We are just calling our Smurfette to a stream that is inside the object class. 120 00:07:19,150 --> 00:07:19,870 OK. 121 00:07:19,870 --> 00:07:22,990 So let's actually run our project and see what happens. 122 00:07:22,990 --> 00:07:26,550 So as you can see here it only put this value here. 123 00:07:26,600 --> 00:07:31,620 OK the name of our package at sign and this number OK. 124 00:07:31,690 --> 00:07:42,130 So let's actually go back inside our chat class and let's actually find the string method that is inside 125 00:07:42,130 --> 00:07:42,960 the Object class. 126 00:07:42,970 --> 00:07:43,570 OK. 127 00:07:43,570 --> 00:07:52,480 So let's actually put this extents object here and then hold the command key on your keyboard and then 128 00:07:52,630 --> 00:07:54,010 click on this object class. 129 00:07:54,070 --> 00:07:59,830 Here if you are using of those machine you need to actually hold the control key on your keyboard and 130 00:07:59,830 --> 00:08:04,350 then click on that object class here instead of math class. 131 00:08:04,360 --> 00:08:04,830 OK. 132 00:08:04,930 --> 00:08:07,400 So as you can see here this is our object class. 133 00:08:07,420 --> 00:08:14,020 So in order to find the string method I just need to actually press on command key plus the f he on 134 00:08:14,020 --> 00:08:15,060 my keyboard. 135 00:08:15,280 --> 00:08:21,200 If you are using a Windows machine you need to actually press on control key plus the key on your keyboard. 136 00:08:21,220 --> 00:08:26,510 And here I can search for it for the method names or for there are two other keyboards. 137 00:08:26,550 --> 00:08:29,410 OK the name of my method is to streambed. 138 00:08:30,070 --> 00:08:34,960 So as you can see here these are two string Meffert OK return gets class. 139 00:08:34,960 --> 00:08:37,070 So let's actually see what's in the emulator. 140 00:08:37,090 --> 00:08:38,800 So this is our emulator OK. 141 00:08:39,010 --> 00:08:43,130 Return get class that get named. 142 00:08:43,810 --> 00:08:47,120 As you can see here this is the name of the package. 143 00:08:47,210 --> 00:08:50,130 Our project this chat here is the name of our class. 144 00:08:50,140 --> 00:08:53,740 OK so return gueth class that get name it returns. 145 00:08:53,810 --> 00:08:55,390 Are this a value here. 146 00:08:55,630 --> 00:08:59,750 The name of our class at sign integer to Hexe. 147 00:08:59,770 --> 00:09:05,560 Strange as you can see here this code here is the result of these quotes here. 148 00:09:05,560 --> 00:09:05,810 OK. 149 00:09:05,830 --> 00:09:08,900 Integer the two hex string hash code. 150 00:09:09,130 --> 00:09:14,010 Ok so you don't need to know whether these are actually values. 151 00:09:14,140 --> 00:09:19,090 I just wanted to show you that this is the default implementation of these Smurfette. 152 00:09:19,270 --> 00:09:27,370 So in order to actually output these values these values that you specified for this chat object to 153 00:09:27,370 --> 00:09:32,300 the screen we need to actually overwrite that to a string method here. 154 00:09:32,500 --> 00:09:39,980 So I just need to type in here to stream as you can see the autocomplete feature of the Android studio 155 00:09:40,230 --> 00:09:41,970 helps us to find that Meffert here. 156 00:09:41,970 --> 00:09:42,510 Okay. 157 00:09:42,570 --> 00:09:46,140 And then I just need to press on return key on my keyboard. 158 00:09:46,240 --> 00:09:51,220 Or if you are using a Windows machine you need to actually press on Enter key on your keyboard. 159 00:09:51,420 --> 00:09:57,630 So as you can see here this is arm twisting method and as you can see it is outside of a right. 160 00:09:57,630 --> 00:10:00,350 Q What here means that we are all the radio. 161 00:10:00,390 --> 00:10:03,510 Or redefining our Meffert that is inside the superclass.