1 00:00:05,320 --> 00:00:08,680 -Hi. In this video, we are going to look at the class counterpart 2 00:00:09,000 --> 00:00:12,520 of the implementors and senders functionalities. 3 00:00:12,840 --> 00:00:14,800 So, let's open the System Browser once more. 4 00:00:15,120 --> 00:00:18,200 So, Tools, System Browser, go to AST-Core, 5 00:00:18,520 --> 00:00:20,720 RBComment, for example, or any other class. 6 00:00:21,040 --> 00:00:24,160 You can right click on the class and go to the Class references. 7 00:00:24,480 --> 00:00:28,560 You can see that it even has the same shortcut as the senders. 8 00:00:28,880 --> 00:00:30,200 So, click on that. 9 00:00:30,520 --> 00:00:33,840 You will have all the references to the RBComment 10 00:00:34,160 --> 00:00:37,560 that are made in bodies of methods in the system. 11 00:00:37,880 --> 00:00:39,400 Right there, we have four of them. 12 00:00:39,720 --> 00:00:42,320 You can investigate them, as with implementors and senders, 13 00:00:42,640 --> 00:00:45,320 and another thing is that this functionality is so useful 14 00:00:45,640 --> 00:00:48,840 that it has its own button in the interface. 15 00:00:49,160 --> 00:00:52,000 So, right here, you can click on it to open the same references. 16 00:00:52,320 --> 00:00:55,520 Another important thing is, when looking at instance variables, 17 00:00:55,840 --> 00:00:56,840 you can highlight them. 18 00:00:57,160 --> 00:00:59,480 Right click, go to Code search. 19 00:00:59,800 --> 00:01:03,600 This will help you have access to senders and implementors as well, 20 00:01:03,920 --> 00:01:06,520 but most importantly, to References to it. 21 00:01:06,840 --> 00:01:08,440 If we look at it, there are basically 22 00:01:08,760 --> 00:01:12,480 all the references to the instance variable contents. 23 00:01:12,800 --> 00:01:14,400 This will really help you understand 24 00:01:14,720 --> 00:01:18,120 how the instance variable is used within the class. 25 00:01:18,440 --> 00:01:21,720 So, those functionalities coupled with the ones of the methods 26 00:01:22,040 --> 00:01:24,320 will really help you understand classes, 27 00:01:24,640 --> 00:01:26,960 their architectures and how they work together, 28 00:01:27,280 --> 00:01:29,560 with the instance variables, how they are sent, 29 00:01:29,880 --> 00:01:32,480 and you can look for examples, which is really important. 30 00:01:32,800 --> 00:01:35,480 You can look for examples using the senders functionality. 31 00:01:35,800 --> 00:01:40,120 So, they have the same shortcut, Cmd+N, to look at the references. 32 00:01:40,440 --> 00:01:42,520 Or you can click on Class refs. 33 00:01:42,840 --> 00:01:46,280 And if you want to look for the references to instance variable, 34 00:01:46,600 --> 00:01:51,120 Shift+Cmd+N will open References to left.