1 00:00:01,080 --> 00:00:07,860 So now in order to actually create another package just click on this as artsy folder and then click 2 00:00:07,860 --> 00:00:11,130 on File New and then click on package. 3 00:00:11,390 --> 00:00:14,490 So for the package name we need our reverse domain here. 4 00:00:14,610 --> 00:00:22,390 So that statement here com that your name dot custom package. 5 00:00:23,090 --> 00:00:23,830 OK. 6 00:00:24,150 --> 00:00:25,800 And then click on finish. 7 00:00:25,950 --> 00:00:29,380 So as you can see here our package is now created. 8 00:00:29,400 --> 00:00:34,170 So now I want to create another class and put that class inside the spy cage. 9 00:00:34,170 --> 00:00:39,800 So just click on this package and then click on File Neal and then click on class. 10 00:00:40,230 --> 00:00:45,640 So for the class name just type in here custom class. 11 00:00:45,770 --> 00:00:46,370 OK. 12 00:00:46,590 --> 00:00:49,150 And for the modifiers choose public. 13 00:00:49,380 --> 00:00:51,440 And here check the sequence here. 14 00:00:51,450 --> 00:00:55,100 Public is static void main method and then click on finish. 15 00:00:55,530 --> 00:00:58,660 So as you can see here our class is now created. 16 00:00:58,830 --> 00:01:02,770 So now I want to actually create an object from the start class. 17 00:01:02,790 --> 00:01:03,280 OK. 18 00:01:03,480 --> 00:01:09,450 So first I need to refer to the name of my class dog and then I need to give my object a name. 19 00:01:09,450 --> 00:01:18,620 For example dog 1 and then I put an assignment operator here and then I use this vote here new. 20 00:01:19,080 --> 00:01:26,790 And then I refer to the name of my class dog and I actually put a pair of round brackets after my class 21 00:01:26,790 --> 00:01:27,020 name. 22 00:01:27,030 --> 00:01:27,450 OK. 23 00:01:27,510 --> 00:01:30,910 And then I need to put in a semicolon at the end of my statement. 24 00:01:31,020 --> 00:01:34,610 So as you can see here it's now showing us an error. 25 00:01:34,620 --> 00:01:39,030 OK so let's hover over the error area and see what's the error. 26 00:01:39,030 --> 00:01:46,890 So as you can see here dog can not be resolved to a type and this means this class doesn't recognize 27 00:01:47,100 --> 00:01:49,230 this dog that Java class. 28 00:01:49,430 --> 00:01:50,140 OK. 29 00:01:50,340 --> 00:01:51,990 It doesn't recognize this class. 30 00:01:52,150 --> 00:01:54,040 OK so what's the problem. 31 00:01:54,090 --> 00:01:59,100 The problem is this custom class that Java is inside this package. 32 00:01:59,130 --> 00:01:59,500 OK. 33 00:01:59,520 --> 00:02:06,660 And this class is inside this package and this class can not refer to the name of its class in order 34 00:02:06,660 --> 00:02:08,080 to create objects. 35 00:02:08,190 --> 00:02:12,330 In other words this class doesn't recognize this class. 36 00:02:12,340 --> 00:02:13,870 Ok inside this package. 37 00:02:13,890 --> 00:02:20,550 So in order to actually allow this class this custom class that Jarba to create objects from this dog 38 00:02:20,830 --> 00:02:30,120 Java class we need to import the address of this dog Java class or the address of this package to this 39 00:02:30,120 --> 00:02:31,650 custom class that Java. 40 00:02:31,800 --> 00:02:33,700 In order to actually access those classes. 41 00:02:33,720 --> 00:02:42,570 Ok so if you for example import the address of this package inside this class we can actually use all 42 00:02:42,570 --> 00:02:45,260 of the classes inside this package. 43 00:02:45,270 --> 00:02:45,830 OK. 44 00:02:45,900 --> 00:02:53,550 But if you only actually import the address of this class to this package you can only actually use 45 00:02:53,610 --> 00:02:56,290 this class inside your custom class that job. 46 00:02:56,310 --> 00:03:03,020 OK so I prefer for now to actually import the address of this package to this class. 47 00:03:03,040 --> 00:03:06,100 Ok inside your custom class that Jobab. 48 00:03:06,180 --> 00:03:08,680 And before the class creation type in here. 49 00:03:08,700 --> 00:03:09,830 Import. 50 00:03:10,410 --> 00:03:11,310 OK. 51 00:03:11,400 --> 00:03:14,370 Come dot Mortaza 52 00:03:17,520 --> 00:03:19,160 getters and setters. 53 00:03:19,200 --> 00:03:29,240 So as you can see here we managed to successfully import the address of this package to our custom class 54 00:03:29,250 --> 00:03:29,980 that Java. 55 00:03:30,090 --> 00:03:32,480 OK this class is inside of this package. 56 00:03:32,490 --> 00:03:33,010 OK. 57 00:03:33,030 --> 00:03:35,540 Can't that mortiser that custom package. 58 00:03:35,550 --> 00:03:36,190 OK. 59 00:03:36,360 --> 00:03:39,110 And now as you can see the error is gone. 60 00:03:39,210 --> 00:03:45,150 OK so we can actually access all of the classes that is inside of this package. 61 00:03:45,150 --> 00:03:46,050 OK. 62 00:03:46,320 --> 00:03:52,130 So now I want to actually access the speed instance variable of these thugs one object. 63 00:03:52,140 --> 00:03:52,910 OK. 64 00:03:53,310 --> 00:03:55,880 And then I want to output that value to the console. 65 00:03:55,950 --> 00:04:04,770 So I just need to type in here a system that out that Pantalone and that inside the prentices I need 66 00:04:04,770 --> 00:04:08,770 to refer to the name of my object Doug. 67 00:04:09,030 --> 00:04:19,690 One that's get speed and then I need to put in a semi-colon at the end of my statement. 68 00:04:19,810 --> 00:04:23,350 So as you can see here it's now showing us an error. 69 00:04:23,350 --> 00:04:30,260 So let's actually hover over the error area and see what's the error the Mefford get speed from the 70 00:04:30,260 --> 00:04:30,650 type. 71 00:04:30,650 --> 00:04:32,560 Doug is not visible. 72 00:04:32,750 --> 00:04:41,690 So as you can see here we cannot refer to the get speed method of this object from this class. 73 00:04:41,690 --> 00:04:44,090 OK so what's the problem. 74 00:04:44,090 --> 00:04:45,150 So let's go inside. 75 00:04:45,250 --> 00:04:46,620 Dog the java file. 76 00:04:46,790 --> 00:04:54,980 As you can see here in this class this method uses the package as it's access modifying the access modifier 77 00:04:54,980 --> 00:05:01,860 of the Smurfette is package and package means that this method is only visible to the whole package. 78 00:05:02,000 --> 00:05:09,800 And it means that this method is only visible to the classes of this package not classes in another 79 00:05:09,800 --> 00:05:10,560 package. 80 00:05:10,850 --> 00:05:19,550 So in order to solve this problem we need to use another access modifier public so public means visible 81 00:05:19,640 --> 00:05:20,660 to the whole world. 82 00:05:20,720 --> 00:05:21,610 OK. 83 00:05:21,740 --> 00:05:27,180 And as you can see here inside the custom cluster Java now the error is gone. 84 00:05:27,340 --> 00:05:27,830 OK. 85 00:05:28,010 --> 00:05:34,970 And I managed to successfully access this get speed method and now I can actually output that value 86 00:05:34,970 --> 00:05:35,680 to the console. 87 00:05:35,780 --> 00:05:43,310 So now if I want to run the code inside this method inside the main effort of this custom class I just 88 00:05:43,310 --> 00:05:49,240 need to right click on this class and then click on run as job application. 89 00:05:49,820 --> 00:05:56,670 So as you can see here disvalue is the value of this speed instance variable of this object. 90 00:05:56,690 --> 00:05:57,520 OK. 91 00:05:57,890 --> 00:06:00,890 And the value of this bit in this variable is 70. 92 00:06:00,890 --> 00:06:01,890 OK. 93 00:06:02,000 --> 00:06:09,140 So that's it that's how you can actually access the instance variables of another class inside another 94 00:06:09,140 --> 00:06:09,580 package. 95 00:06:09,590 --> 00:06:10,930 OK you can see here. 96 00:06:11,180 --> 00:06:12,130 This is public. 97 00:06:12,140 --> 00:06:16,400 Or create a public access modifier means visible to the whole world. 98 00:06:16,640 --> 00:06:23,210 And when you use the public access modifier on MFL or on a variable that Mefford or valuable is going 99 00:06:23,210 --> 00:06:26,580 to be visible to all the java files of that project. 100 00:06:26,630 --> 00:06:31,240 OK so the next access modifier which is very important is private. 101 00:06:31,430 --> 00:06:38,690 So remember that inside the mind that Java class I could successfully access the instance variables 102 00:06:38,750 --> 00:06:41,890 of this my first talk object directly. 103 00:06:41,990 --> 00:06:42,690 OK. 104 00:06:42,950 --> 00:06:50,180 And this is the code that proves that I can't directly access the speed instance variable directly. 105 00:06:50,200 --> 00:06:53,090 OK so now let me actually delete this line of code here. 106 00:06:53,210 --> 00:07:00,500 In order not to allow any other classes other than this thug class to access its instance variables 107 00:07:00,500 --> 00:07:06,910 directly we need to use an ORDER access modifier which is private. 108 00:07:07,010 --> 00:07:10,760 So now let's go inside the main Java class. 109 00:07:10,760 --> 00:07:14,050 So as you can see here it's now showing us an error. 110 00:07:14,060 --> 00:07:14,460 OK. 111 00:07:14,600 --> 00:07:21,480 So as you can see here this class doesn't recognize this speed instance variable no longer. 112 00:07:21,650 --> 00:07:29,780 OK so we cannot actually access this speed instance valuable directly because we used these private 113 00:07:29,900 --> 00:07:37,640 access modifier and this access modifier private means that this variable is only visible inside of 114 00:07:37,640 --> 00:07:38,510 this class. 115 00:07:38,600 --> 00:07:40,430 Ok inside of this Java. 116 00:07:40,490 --> 00:07:41,130 OK. 117 00:07:41,360 --> 00:07:46,060 And we cannot use this instance variable from any places other than this class. 118 00:07:46,090 --> 00:07:49,250 Ok this instance valuable is private. 119 00:07:49,250 --> 00:07:57,200 So in order to actually access the value of the speed instance variable we must use this get help method. 120 00:07:57,200 --> 00:07:59,080 OK great speed. 121 00:07:59,090 --> 00:08:06,590 So now if I want to actually correct this error I just need to delete this speed instance variable and 122 00:08:06,590 --> 00:08:10,850 then I need to refer to the name of my get speed Meffert. 123 00:08:11,000 --> 00:08:17,170 So now I can actually access the value of that speed instance variable. 124 00:08:17,180 --> 00:08:24,120 So now if I get on my project as you can see the value of this sweet instance variable is 70. 125 00:08:24,350 --> 00:08:30,130 OK so that's how you can actually use the access modifiers in your codes. 126 00:08:30,280 --> 00:08:37,150 OK we've got another access modifier in Java which I'll tell you more about in the next tutorials. 127 00:08:37,160 --> 00:08:37,580 OK. 128 00:08:37,640 --> 00:08:44,680 Now I want to actually tell you another important point about running our Java projects. 129 00:08:44,740 --> 00:08:53,420 Ok so now if I actually write you click on these get hairs and set her project as you can see here and 130 00:08:53,420 --> 00:08:58,730 then click on runners and then click on Java application. 131 00:08:58,730 --> 00:09:02,230 So as you can see here it's now showing us this window here. 132 00:09:02,240 --> 00:09:02,790 OK. 133 00:09:02,870 --> 00:09:13,340 And here it says matching items main dash cam that Mortaza dot getters and setters workspace matches 134 00:09:14,270 --> 00:09:18,950 custom class dash cam that mortars or that custom package. 135 00:09:18,950 --> 00:09:25,860 So as you can see here because we've got two main methods inside of these classes the main class and 136 00:09:25,860 --> 00:09:31,970 the custom class it's now asking us to determine which one of the classes we want to run. 137 00:09:31,970 --> 00:09:38,870 So if I actually click on this option here it's going to actually run the codes inside the main method 138 00:09:39,110 --> 00:09:40,570 that is inside the main class. 139 00:09:40,580 --> 00:09:41,240 OK. 140 00:09:41,450 --> 00:09:42,330 As you can see here. 141 00:09:42,530 --> 00:09:48,450 But if we actually choose this option here it's going to actually run the code inside the main method. 142 00:09:48,500 --> 00:09:50,860 Inside the custom class that job. 143 00:09:50,870 --> 00:09:51,490 OK. 144 00:09:51,500 --> 00:09:56,730 So here I can actually choose which one of these classes I want to run. 145 00:09:56,740 --> 00:09:57,170 OK. 146 00:09:57,200 --> 00:10:04,520 So if I actually choose this option and then click on OK it's going to actually execute the code inside 147 00:10:04,790 --> 00:10:08,430 of the main effect of this main class. 148 00:10:08,450 --> 00:10:08,900 OK.