1 00:00:00,790 --> 00:00:01,610 Hi everyone. 2 00:00:01,630 --> 00:00:06,790 So let's create a new class called Taxi manager inside our project. 3 00:00:06,850 --> 00:00:11,550 So at the top and you just click on view to the windows and then click on project here. 4 00:00:11,590 --> 00:00:17,950 Just open this app folder open this job folder and when cities first package here right just right click 5 00:00:17,950 --> 00:00:21,180 on this package that actually contains this make me an activity class. 6 00:00:21,280 --> 00:00:24,710 Right click on this package new and then click on Dobber class. 7 00:00:24,730 --> 00:00:34,920 So for the name of the class just type in here taxi manager taxi manager and here let's actually specify 8 00:00:35,000 --> 00:00:37,010 you can see that this kind is class. 9 00:00:37,050 --> 00:00:37,350 OK. 10 00:00:37,350 --> 00:00:41,520 Make sure that it is actually the class and here don't change anything. 11 00:00:41,610 --> 00:00:46,510 The visibility is public and the modifier is not just going to kind of key. 12 00:00:46,520 --> 00:00:49,760 So here we have this class called Taxi manager. 13 00:00:49,760 --> 00:00:51,230 So let's go inside this class. 14 00:00:51,350 --> 00:00:53,120 Let me actually double click on this top here. 15 00:00:53,120 --> 00:00:57,240 Taxi manager's job up in order to make this area wider. 16 00:00:57,260 --> 00:01:02,230 So inside this class inside the credibility of this class first let's create some valuables. 17 00:01:02,270 --> 00:01:07,820 So the first variable that I am going to create is going to be a private as you can see that the access 18 00:01:07,820 --> 00:01:13,850 to the fire is private and the data type is going to be off the location and the name of this variable 19 00:01:14,060 --> 00:01:20,560 is going to be destination location destination location right semi-colon. 20 00:01:20,710 --> 00:01:25,920 So this is our first value but and as you can see if it is not initialized yet we do not initialize 21 00:01:25,980 --> 00:01:26,900 this valuable yet. 22 00:01:27,040 --> 00:01:29,830 So now let's create a new method here. 23 00:01:29,830 --> 00:01:34,840 Actually it is called a set here for this destination location instance variable. 24 00:01:35,050 --> 00:01:42,010 So now I can say Puplick void and the name of this value is going to be set destination location and 25 00:01:42,010 --> 00:01:43,670 put up her of here. 26 00:01:43,690 --> 00:01:47,950 So if you're going to provide a parameter for this method which is going to be off their location and 27 00:01:47,950 --> 00:01:54,870 the value is going to be destination destination location and an open and close. 28 00:01:54,870 --> 00:02:01,140 This method by using the curly braces so you can see that the name of our instance variable is the initial 29 00:02:01,140 --> 00:02:07,530 location and this name is actually exactly the same as the name of our promoter. 30 00:02:07,620 --> 00:02:13,680 So in this case we must put this dot destination location. 31 00:02:13,680 --> 00:02:19,620 So when I say this that this initial location I am referring to this instance variable of this taxi 32 00:02:19,620 --> 00:02:24,100 manager class this refers to an instance of taxi manager. 33 00:02:24,300 --> 00:02:29,790 So when I say this that this initial location is going to refer to this instance variable assignment 34 00:02:29,790 --> 00:02:35,600 operator and now I can assign this this initial location this parameter to this instance variable. 35 00:02:35,610 --> 00:02:44,410 So here I can see actually I can assign this parameter as an argument to this instance value but this 36 00:02:44,430 --> 00:02:45,780 initial location. 37 00:02:45,780 --> 00:02:52,170 So now after the end calibers of this sector and before the really cold embrace of this task manager 38 00:02:52,170 --> 00:02:54,660 class that actually puts more lines of code here. 39 00:02:54,900 --> 00:03:00,780 So here let's create another team effort so that they can hear Puplick and their return type of this 40 00:03:00,780 --> 00:03:08,010 method is going to be float the name of the Smurfit is going to be return that this then is returned 41 00:03:08,010 --> 00:03:20,120 a distance to destination location destination location in meters right and put up at Apprentice's. 42 00:03:20,130 --> 00:03:23,430 So this is going to accept an identity and argument. 43 00:03:23,460 --> 00:03:27,930 So if you need to specify that parameter here which is going to be off the up location and the name 44 00:03:27,930 --> 00:03:35,360 of this parameter is going to be current location current location and just open and close the Smurfette 45 00:03:35,540 --> 00:03:37,360 by using these curly braces. 46 00:03:37,490 --> 00:03:40,100 So that may actually create some space here. 47 00:03:41,220 --> 00:03:48,550 Now I can create an if statement here so I can't say current location is not equal to null. 48 00:03:48,840 --> 00:03:52,230 So if you are going to check that it is called defensive programming. 49 00:03:52,230 --> 00:03:57,710 First we must make sure that these are actually location objects are not null. 50 00:03:57,830 --> 00:03:58,250 OK. 51 00:03:58,260 --> 00:04:00,480 Otherwise our application may crash. 52 00:04:00,480 --> 00:04:04,820 So first let's actually make sure that this current location is which is actually the parameter right. 53 00:04:04,860 --> 00:04:10,870 It is null and then we must make sure that the destination location which is actually an instance variable 54 00:04:10,870 --> 00:04:11,500 right. 55 00:04:11,580 --> 00:04:16,590 It is actually also not null so not null. 56 00:04:16,680 --> 00:04:25,510 Only in that case we can actually go inside this if statement and then we can return current location 57 00:04:25,820 --> 00:04:32,750 that distance to and then we need to specify the destination location right so that its initial location 58 00:04:32,750 --> 00:04:35,420 is going to be this one this initial location semi-colon. 59 00:04:35,420 --> 00:04:37,340 So this is actually a predefined method. 60 00:04:37,370 --> 00:04:43,940 The distance to my feet is a predefined method of this location class that we can actually use in order 61 00:04:44,150 --> 00:04:52,130 to actually get the distance of actually from the current location to the destination location in meters. 62 00:04:52,280 --> 00:04:55,440 Okay this is going to return a float value of floating point value. 63 00:04:55,580 --> 00:05:02,000 So the first say current location data distance to destination location and thats as simple as that. 64 00:05:02,180 --> 00:05:08,570 So what happens if current location is for example Nol or for example this the initial location is not 65 00:05:08,660 --> 00:05:12,500 in that case you are going to have an else statement. 66 00:05:12,640 --> 00:05:18,070 So I just open and close this statement by using the curly braces and here I can see return. 67 00:05:18,100 --> 00:05:20,650 So we need to adjust the return of floating point value. 68 00:05:20,660 --> 00:05:24,820 So here I just are just going to return up the actual negative value. 69 00:05:24,820 --> 00:05:29,450 So for example return one hundred point zero if. 70 00:05:29,540 --> 00:05:31,440 OK so this is of type float. 71 00:05:31,480 --> 00:05:35,660 We must put this letter F here at the end of this value semicolon. 72 00:05:35,920 --> 00:05:36,480 Right. 73 00:05:36,820 --> 00:05:38,070 So thats it. 74 00:05:38,100 --> 00:05:39,120 Lets actually. 75 00:05:39,140 --> 00:05:40,420 So this is our man for the right. 76 00:05:40,420 --> 00:05:41,780 Let's create another method. 77 00:05:41,770 --> 00:05:47,290 So after the curly brace of this method and before the end in calibrates of this class I'm going to 78 00:05:47,290 --> 00:05:52,880 create another method here the access money for you that I am going to create is going to be public 79 00:05:53,300 --> 00:05:56,830 the return type of this method is going to be streamed. 80 00:05:56,840 --> 00:06:00,090 So this method must return a value of type string. 81 00:06:00,230 --> 00:06:08,650 And then in the name of this it is going to be returned return the miles between 82 00:06:11,400 --> 00:06:16,320 current location and this the nation location 83 00:06:20,780 --> 00:06:24,190 and it's actually quite a bit of practices here. 84 00:06:24,230 --> 00:06:28,680 So now we need to specify the parameters of this method right. 85 00:06:29,960 --> 00:06:36,140 So the first trimester of this Smurfette is going to be off site location and the name is going to be 86 00:06:36,140 --> 00:06:39,310 cut into location right karma. 87 00:06:39,890 --> 00:06:45,810 And the second location is going to be of type integer so it and the name of this valuable and shoot 88 00:06:45,820 --> 00:06:50,840 the name of this primary is going to be meters per mile. 89 00:06:51,320 --> 00:06:51,830 Right. 90 00:06:51,830 --> 00:06:55,190 So let's actually open and close this method by using these curly braces. 91 00:06:55,190 --> 00:06:59,990 Let me actually create a new line here so you can see it is my fifth year entirely. 92 00:06:59,990 --> 00:07:00,920 This is the name of the method. 93 00:07:00,940 --> 00:07:03,490 And these these are the two promoters of this method right. 94 00:07:03,680 --> 00:07:06,870 So let's go inside the curly braces of the Smurfit. 95 00:07:06,920 --> 00:07:13,400 So let's create valuable of that interior so it and the name of this variable is going to be Miles assignment 96 00:07:13,400 --> 00:07:14,240 operator. 97 00:07:14,630 --> 00:07:20,810 And let's actually we are going to actually get a floating point a floating value but we need to cast 98 00:07:20,810 --> 00:07:25,640 it to an integer value in order to assign it to odd integer value but here the. 99 00:07:25,700 --> 00:07:29,410 So here I can actually put a pair of parenthesis and right. 100 00:07:29,680 --> 00:07:37,610 And now I can put up another prof practices here and I can defer to the Smurfette he returned the distance 101 00:07:37,610 --> 00:07:39,490 to destination location in meters. 102 00:07:39,500 --> 00:07:45,560 So let's actually refer to this Meffert return the distance to destination location in meters. 103 00:07:45,830 --> 00:07:48,490 And now we need to pass the current location to dismiss it. 104 00:07:48,490 --> 00:07:49,190 Right. 105 00:07:49,220 --> 00:07:56,950 So I can't say Konitz location and here you can see that we have this Meffert and we passed the current 106 00:07:56,950 --> 00:08:02,680 location divided by meters Hermite meters per mile. 107 00:08:02,890 --> 00:08:09,520 So this formula this is actually a formula that you are not actually expected to know mathematics in 108 00:08:09,520 --> 00:08:11,530 order to actually use this formula. 109 00:08:11,530 --> 00:08:16,180 This is the formula you can use it whenever you want it where ever you want when you want to actually 110 00:08:16,180 --> 00:08:21,190 create an Android application in order to for example get the miles between the current location and 111 00:08:21,190 --> 00:08:22,490 the destination location. 112 00:08:22,550 --> 00:08:28,640 First you need to actually get that distance emitters from the current location to the destination location 113 00:08:28,960 --> 00:08:35,450 and then you need to divide that value to the value of the meters per mile that the user wants actually 114 00:08:35,450 --> 00:08:36,700 to for example travel. 115 00:08:36,790 --> 00:08:40,690 So if you get this meters per mile as that as an argument from the Smurfette here. 116 00:08:40,690 --> 00:08:41,420 Right. 117 00:08:41,450 --> 00:08:46,390 So and then we cast it to an integer value and we assign it to this variable of 10 miles. 118 00:08:46,600 --> 00:08:48,070 So we have the Miles you're right. 119 00:08:48,070 --> 00:08:50,970 Let me actually create another new line here. 120 00:08:51,460 --> 00:09:01,520 So let me just actually put this new line here so that you can see the entire piece of code here right 121 00:09:02,060 --> 00:09:03,570 now that we have Miles. 122 00:09:03,680 --> 00:09:11,840 Let's create an if statement so if Miles is actually equal to number one if there is only one one mile 123 00:09:11,840 --> 00:09:20,110 between the current location and the destination location I can just say return one might. 124 00:09:20,170 --> 00:09:21,510 So we're going to return. 125 00:09:21,610 --> 00:09:26,490 One might this value this string value from this method if the miles is actually equal to one. 126 00:09:26,850 --> 00:09:29,280 So let's create an ELSE IF statement else. 127 00:09:29,320 --> 00:09:36,870 If at inside Apprentice's I can say LCF Miles is actually greater than one. 128 00:09:36,990 --> 00:09:45,480 In that case we are going to say return miles plus and let's actually put a pair of Cozzi at these two 129 00:09:45,480 --> 00:09:50,950 double quotes and here I put our space here and then I can say Miles semi-colon. 130 00:09:51,030 --> 00:09:55,290 So it's going to get the value of the Miles value of it and it's going to actually concatenated this 131 00:09:55,290 --> 00:09:57,780 value of the value of the miles here. 132 00:09:57,780 --> 00:10:02,550 So we're going to return this value from this actually else if statement let's actually create an else 133 00:10:02,550 --> 00:10:03,500 statement. 134 00:10:03,630 --> 00:10:09,870 If none of the conditions above is actually true then we are going to execute this Ellis statement here. 135 00:10:10,790 --> 00:10:18,510 So he can't just return to cotes I can't say no mind no mind or Miles semi-colon. 136 00:10:18,680 --> 00:10:19,490 OK. 137 00:10:19,580 --> 00:10:26,870 So that this is on my feet and let's actually create another fit inside our taxi manager class. 138 00:10:26,870 --> 00:10:31,090 So after the ending calibers of this method I'm going to create another fit in the next tutorial. 139 00:10:31,140 --> 00:10:33,350 You can actually continue building this application. 140 00:10:33,350 --> 00:10:34,700 Thanks very much for watching. 141 00:10:34,700 --> 00:10:40,010 If you have any questions please put the discussion into Course and then I'll do my best to answer all 142 00:10:40,010 --> 00:10:41,030 of your questions.