1 00:00:00,370 --> 00:00:07,140 This that operating system assignments operator operating system does start a Super Power assignment 2 00:00:07,170 --> 00:00:09,830 operator Sibiu power and does that RAM. 3 00:00:09,900 --> 00:00:10,440 OK. 4 00:00:10,580 --> 00:00:13,240 Assignment operator ram OK. 5 00:00:13,680 --> 00:00:15,420 So hopefully that makes sense. 6 00:00:15,570 --> 00:00:18,270 And now is actually putting some more lines of code here. 7 00:00:18,300 --> 00:00:24,670 So as you can see here I have a get her get her for this operating system instance variable. 8 00:00:24,720 --> 00:00:25,260 OK. 9 00:00:25,350 --> 00:00:28,930 And then I have a here for this operating system instance variable. 10 00:00:29,010 --> 00:00:29,680 OK. 11 00:00:30,000 --> 00:00:32,670 And then I have another get here for this. 12 00:00:32,680 --> 00:00:39,150 So if you power instance malleable and I have a set here for this Sibiu power an instance variable and 13 00:00:39,150 --> 00:00:43,650 inside of set for a first about I actually created an if statement. 14 00:00:43,650 --> 00:00:50,490 If the value of these CPO power is less than or equal to number 0 or if the value of this argument is 15 00:00:50,490 --> 00:00:57,450 less than or equal to number 0 then throw a new illegal argument exception the value of this Depue power 16 00:00:57,630 --> 00:00:59,470 must be greater than zero. 17 00:00:59,460 --> 00:00:59,900 OK. 18 00:00:59,970 --> 00:01:03,900 And then here I am actually instantiating this instance variable. 19 00:01:03,960 --> 00:01:06,760 Does that power power Sibiu power. 20 00:01:06,930 --> 00:01:07,480 OK. 21 00:01:07,860 --> 00:01:16,650 And here I actually created a getter for this instance variable and here I actually created a set for 22 00:01:16,650 --> 00:01:17,970 this instance variable. 23 00:01:18,000 --> 00:01:24,840 And again I created another if statement if the value of this ram argument as you can see here is less 24 00:01:24,840 --> 00:01:31,330 than or equal to number 0 then Frode new illegal argument exception then the value of the must be greater 25 00:01:31,350 --> 00:01:32,350 than zero. 26 00:01:32,580 --> 00:01:38,710 And here I actually initialized this instance variable at the start of the assignment operator. 27 00:01:38,790 --> 00:01:45,690 So here if the user of this settlement actually are assigned an invalid number. 28 00:01:45,800 --> 00:01:47,200 OK that is one example. 29 00:01:47,340 --> 00:01:49,650 Equal or less than number. 30 00:01:49,710 --> 00:01:51,710 Then that application is going to crash. 31 00:01:51,770 --> 00:02:00,520 OK so now let's actually implement the inherited method that we actually have that actually that is 32 00:02:00,520 --> 00:02:02,240 inside of this computer class. 33 00:02:02,280 --> 00:02:02,570 OK. 34 00:02:02,600 --> 00:02:04,210 Evaluate performance. 35 00:02:04,230 --> 00:02:08,450 So here I just need to type in evaluate a performance. 36 00:02:08,450 --> 00:02:14,180 Now as you can see if you are writing this Moffats or just delete this line of code here and inside 37 00:02:14,180 --> 00:02:17,000 of this method and actually putting our own code here. 38 00:02:17,040 --> 00:02:17,440 OK. 39 00:02:17,490 --> 00:02:23,790 So here inside of this method as you can see I am returning the result of multiplication of these two 40 00:02:23,790 --> 00:02:27,200 instance variables so power multiplied by Ram. 41 00:02:27,360 --> 00:02:33,390 OK so another important point about is these exceptions that are remember that these are. 42 00:02:33,480 --> 00:02:35,480 This is not the right way to write your code. 43 00:02:35,520 --> 00:02:35,980 OK. 44 00:02:36,210 --> 00:02:40,790 But here I just wanted to show you how you can actually use exceptions in your projects. 45 00:02:40,800 --> 00:02:46,710 Ok so now let's actually overwrite the two string method that you actually inherit from the computer 46 00:02:46,710 --> 00:02:47,240 class. 47 00:02:47,310 --> 00:02:53,270 So now let's actually delete this line of code here and now we can actually put in our own implementations 48 00:02:53,310 --> 00:02:53,780 here. 49 00:02:53,970 --> 00:02:58,770 So now I'm going to actually putting a piece of code here and then I'm going to explain to you what's 50 00:02:58,770 --> 00:02:59,600 going on here. 51 00:02:59,640 --> 00:03:00,100 OK. 52 00:03:00,150 --> 00:03:05,700 So as you can see here I am saying that the return string data formats and inside of these double quotes 53 00:03:05,790 --> 00:03:08,570 I am specifying the format of my string value. 54 00:03:08,640 --> 00:03:15,390 So here as you can see this percent as here is actually referring to this super that string here. 55 00:03:15,780 --> 00:03:24,520 And this person here person S is for this spew power here and here is a person f is actually for the 56 00:03:24,570 --> 00:03:25,620 small numbers. 57 00:03:25,650 --> 00:03:27,640 So this is for get Sibiu power. 58 00:03:27,720 --> 00:03:28,320 OK. 59 00:03:28,470 --> 00:03:31,990 Sibiu power instance Raddy but actually is of type double. 60 00:03:32,010 --> 00:03:32,720 OK. 61 00:03:33,000 --> 00:03:35,630 And we have another percent end here. 62 00:03:35,850 --> 00:03:39,710 This is a new line character person as this is for RAM. 63 00:03:39,700 --> 00:03:41,840 Here it is for lab here. 64 00:03:42,000 --> 00:03:44,570 This string by the string value. 65 00:03:44,580 --> 00:03:45,290 OK. 66 00:03:45,540 --> 00:03:48,670 And we have another percent here. 67 00:03:48,720 --> 00:03:50,400 This is for kids right here. 68 00:03:50,430 --> 00:03:51,120 OK. 69 00:03:51,600 --> 00:03:53,290 So hopefully that makes sense. 70 00:03:53,310 --> 00:03:58,410 And now let's actually go inside this tablet computer here tablet computer that of a fine. 71 00:03:58,560 --> 00:04:04,490 And now after the class named after this tablet tablet our computer class name he has just stepped in 72 00:04:04,510 --> 00:04:07,440 he had extents smartphone computer. 73 00:04:07,620 --> 00:04:08,050 OK. 74 00:04:08,130 --> 00:04:14,880 So that is actually and is our relationship between these two classes a tablet computer is our smart 75 00:04:15,060 --> 00:04:16,200 phone computer. 76 00:04:16,290 --> 00:04:17,070 OK. 77 00:04:17,400 --> 00:04:18,980 So hopefully that makes sense. 78 00:04:18,990 --> 00:04:22,340 And he and as you can see this is actually showing us an error. 79 00:04:22,470 --> 00:04:30,090 And if I hover my mouse pointer over the area it says there is not a default constructor available in 80 00:04:30,180 --> 00:04:32,640 actually smart one computer class. 81 00:04:32,850 --> 00:04:37,710 Ok so here I need to actually put in some instance variables. 82 00:04:37,710 --> 00:04:38,120 OK. 83 00:04:38,160 --> 00:04:44,610 So as you can see here this is my instance variable that is specific only to this tablet computer class 84 00:04:44,880 --> 00:04:47,260 private int screen size. 85 00:04:47,340 --> 00:04:51,600 And as you can see here I didn't instantiate this instance variable here. 86 00:04:51,630 --> 00:04:57,740 OK so here let's actually create a constructor for this tablet computer class OK. 87 00:04:58,050 --> 00:05:03,440 And as you can see here this is my constructor for this tablet computer class. 88 00:05:03,520 --> 00:05:04,030 OK. 89 00:05:04,240 --> 00:05:09,380 And this constructed actually accepts some arguments name screen keyboard. 90 00:05:09,490 --> 00:05:10,070 OK. 91 00:05:10,300 --> 00:05:17,600 And here you have this argument operating system Sibiu power RAM and screen size. 92 00:05:17,620 --> 00:05:18,160 OK. 93 00:05:18,310 --> 00:05:23,800 And here because we are actually inheriting all of the features and behaviors that are actually inside 94 00:05:23,800 --> 00:05:30,100 of these smart phone computer class we need to actually initialize the constructor of the superclass. 95 00:05:30,100 --> 00:05:35,840 So super name screen keyboard operating system Sibiu power Lamhe. 96 00:05:36,190 --> 00:05:36,840 OK. 97 00:05:37,090 --> 00:05:41,410 And these are the arguments that this smartphone computer constructive needs. 98 00:05:41,410 --> 00:05:41,910 OK. 99 00:05:42,040 --> 00:05:43,030 As you can see here. 100 00:05:43,270 --> 00:05:43,880 OK. 101 00:05:44,170 --> 00:05:50,160 And now we have actually an instance variable screen size. 102 00:05:50,410 --> 00:05:54,180 And here as you can see this is our argument screen size here. 103 00:05:54,370 --> 00:06:01,240 And here I actually created an if statement if the value of this screen size argument is less than or 104 00:06:01,270 --> 00:06:02,810 equal to number 0. 105 00:06:02,890 --> 00:06:04,480 Then a new legal argument. 106 00:06:04,480 --> 00:06:08,970 Exception the screen size must be greater than number 0. 107 00:06:08,980 --> 00:06:09,470 OK. 108 00:06:09,700 --> 00:06:11,780 So here I just need to type in greater. 109 00:06:12,130 --> 00:06:20,170 And as you can see here and I actually instantiated this instance valuable destock screen size assignment 110 00:06:20,200 --> 00:06:21,790 operator screen size. 111 00:06:22,180 --> 00:06:28,720 And now this actually creates our getter and asserter for this screen size instance variable. 112 00:06:28,720 --> 00:06:34,890 So just right click here and say that this class generates getter and setter screen size. 113 00:06:34,960 --> 00:06:35,780 OK. 114 00:06:36,100 --> 00:06:42,040 So this is the so these are actually that are getter and the Center for our own instance variable. 115 00:06:42,340 --> 00:06:45,260 And as you can see here it doesn't show us any error. 116 00:06:45,310 --> 00:06:46,130 OK. 117 00:06:46,210 --> 00:06:52,870 Because this smartphone or computer class as you can see here is inheriting all of the features and 118 00:06:52,870 --> 00:06:56,290 behaviors that are inside of these abstract computer class. 119 00:06:56,350 --> 00:06:56,760 OK. 120 00:06:56,830 --> 00:07:04,460 And inside of these are smartphone or computer class I actually implemented this evaluate performance 121 00:07:04,470 --> 00:07:04,880 Smiffy. 122 00:07:04,900 --> 00:07:09,470 This is actually an abstract method OK inside of a tablet computer class. 123 00:07:09,510 --> 00:07:13,320 We actually don't need to again implement that method. 124 00:07:13,530 --> 00:07:13,850 OK. 125 00:07:13,870 --> 00:07:20,030 Inside of these tablets computer class I don't need to actually implement that method again. 126 00:07:20,280 --> 00:07:20,720 OK. 127 00:07:20,770 --> 00:07:27,190 If you don't want to actually change the implementation of this method OK because I actually inherit 128 00:07:27,280 --> 00:07:32,970 all of the features and behaviors that are actually inside of this smart phone computer class or case 129 00:07:33,280 --> 00:07:35,400 I actually inherit this method here. 130 00:07:35,470 --> 00:07:35,700 OK. 131 00:07:35,710 --> 00:07:37,280 And this implementation. 132 00:07:37,450 --> 00:07:43,690 And if I don't want to actually change this implementation inside of this tablet computer class I don't 133 00:07:43,690 --> 00:07:46,840 need to actually overwrite that method here again. 134 00:07:46,930 --> 00:07:54,070 And if I actually call this method this evaluate performance Smurfit on an object of this tablet computer 135 00:07:54,070 --> 00:08:00,040 class is going to actually return the result of my multiplication of the value of the C-u power and 136 00:08:00,040 --> 00:08:01,550 the value of the land to me. 137 00:08:01,630 --> 00:08:08,810 OK so now let's actually overwrite the two string method here inside of this tablet computer class. 138 00:08:09,250 --> 00:08:09,780 OK. 139 00:08:09,940 --> 00:08:12,650 And delete this implementation inside of this method. 140 00:08:12,790 --> 00:08:17,580 And now we can actually put in our own implementations inside of these two string Meffert. 141 00:08:17,590 --> 00:08:22,750 So as you can see here I'm going to actually pasting a piece of code here and then I'm going to explain 142 00:08:22,750 --> 00:08:24,150 to you what's going on here. 143 00:08:24,430 --> 00:08:27,530 So as you can see here it says Return string format. 144 00:08:27,670 --> 00:08:28,190 OK. 145 00:08:28,310 --> 00:08:32,860 And say that the double quotes I am specifying the format of my string value. 146 00:08:32,920 --> 00:08:33,420 Percent. 147 00:08:33,430 --> 00:08:34,720 S is for super. 148 00:08:34,720 --> 00:08:35,560 That was 3M. 149 00:08:35,680 --> 00:08:38,480 So remember super is referring to the superclass. 150 00:08:38,490 --> 00:08:42,360 So in this case the superclass is smartphone computer OK. 151 00:08:42,430 --> 00:08:45,980 And inside of this smart phone computer we have these two three method. 152 00:08:46,000 --> 00:08:47,120 As you can see here. 153 00:08:47,170 --> 00:08:49,780 So it's going to actually return this string value to me. 154 00:08:49,780 --> 00:08:50,340 OK. 155 00:08:50,440 --> 00:08:56,770 So you support that with strong super strength Sibiu power gets you power as you can see here and ram 156 00:08:56,930 --> 00:08:58,110 Guthrum OK. 157 00:08:58,480 --> 00:09:04,330 And here as you can see inside of these two string Meffert we are referring to the Super Tuesday. 158 00:09:04,330 --> 00:09:08,050 So it's connected to return that string value to us percent. 159 00:09:08,060 --> 00:09:14,860 And this is actually a new line character and we have another person as he he here screen size colon 160 00:09:15,910 --> 00:09:17,550 and we have person here. 161 00:09:17,550 --> 00:09:22,690 So this gets screen size here as you can see returns a value of type integer. 162 00:09:22,690 --> 00:09:25,540 OK so personally is for arguments of type integer. 163 00:09:25,540 --> 00:09:26,180 OK. 164 00:09:26,740 --> 00:09:32,210 And now let's actually go back inside the main activity that job fine here and now we've been actually 165 00:09:32,230 --> 00:09:33,800 putting some lines of code here. 166 00:09:33,820 --> 00:09:40,640 So here inside of this uncreate method let's actually create some objects from the text class. 167 00:09:40,900 --> 00:09:41,400 OK. 168 00:09:41,620 --> 00:09:46,230 As you can see here I created some objects from these are text for your class. 169 00:09:46,240 --> 00:09:52,110 So as you can CTX the desktop computer and here I referred to the name of this idea or that identity. 170 00:09:52,210 --> 00:09:56,590 The desktop computer SD takes the laptop computer. 171 00:09:56,590 --> 00:10:05,350 And here I refer to this ID are that ID the laptop computer geeks the smart one computer or the smartphone 172 00:10:05,370 --> 00:10:10,380 computer takes the tablet computer art that's 86 that tablet computer. 173 00:10:10,470 --> 00:10:17,910 And here as you can see the desktop computer performance takes the desktop computer performance takes 174 00:10:17,940 --> 00:10:24,290 the laptop computer performance and as you can see are that I.D. takes the laptop computer performance. 175 00:10:24,330 --> 00:10:28,670 And here we have this theory the smart phone computer performance. 176 00:10:28,800 --> 00:10:33,810 And here I have art that Id thought TXI the smartphone computer performance. 177 00:10:33,810 --> 00:10:40,600 And here I have the XTi tablet computer performance and here as you can see the tablet computer performance 178 00:10:40,600 --> 00:10:41,100 is OK.