1 00:00:00,360 --> 00:00:00,990 All right. 2 00:00:00,990 --> 00:00:03,060 Let us just jump right into it. 3 00:00:03,060 --> 00:00:05,340 So here we've got two functions. 4 00:00:05,370 --> 00:00:07,950 This one returns a double when called. 5 00:00:07,980 --> 00:00:10,260 This one returns a string, one called. 6 00:00:10,260 --> 00:00:13,890 But for the sake of variety, let us add another function. 7 00:00:14,310 --> 00:00:18,330 But this one, unlike these two, is not going to return a value. 8 00:00:18,360 --> 00:00:20,640 You guessed it, it's going to be void. 9 00:00:20,640 --> 00:00:24,360 And this void function is going to be called print area. 10 00:00:24,360 --> 00:00:29,490 And this function is not only going to print the area, but the length and width that we're used to 11 00:00:29,490 --> 00:00:30,690 produce that area. 12 00:00:30,690 --> 00:00:40,620 So it's going to need to define three parameters double length, double width and double area. 13 00:00:42,010 --> 00:00:47,860 And you might be wondering why is this function void and why are these returning values? 14 00:00:48,010 --> 00:00:50,170 I will get to that in just a second. 15 00:00:50,170 --> 00:00:52,000 But bear with me here. 16 00:00:52,000 --> 00:00:53,200 We're just going to print. 17 00:00:55,020 --> 00:01:01,080 Um, a rectangle with a length of. 18 00:01:02,140 --> 00:01:03,040 Length. 19 00:01:05,660 --> 00:01:09,680 And a width of width. 20 00:01:13,710 --> 00:01:16,290 As an area of. 21 00:01:17,000 --> 00:01:19,760 Whatever area that gets passed in. 22 00:01:20,490 --> 00:01:21,150 Okay. 23 00:01:22,670 --> 00:01:26,300 So why is this void and why is this returning a value? 24 00:01:26,300 --> 00:01:28,010 And why is this returning a value? 25 00:01:28,400 --> 00:01:34,010 Well, as I mentioned before, a function should only be performing a single task. 26 00:01:34,160 --> 00:01:37,890 This one performs the task of calculating an area. 27 00:01:37,910 --> 00:01:41,070 The function is already performing a computation. 28 00:01:41,090 --> 00:01:45,830 It should not be the one to also handle the final result of that computation. 29 00:01:45,980 --> 00:01:51,920 It should return the final result and let whoever is calling the function to deal with that result as 30 00:01:51,920 --> 00:01:53,090 they see fit. 31 00:01:53,720 --> 00:01:56,960 The explained area function is performing one task. 32 00:01:56,990 --> 00:02:02,930 It takes in a language and based on the provided language, it compares it against three possible cases 33 00:02:02,930 --> 00:02:06,260 and it explains the area in their preferred language. 34 00:02:06,500 --> 00:02:08,560 This is a form of computation. 35 00:02:08,570 --> 00:02:14,210 The function is already doing so much work, so it should not be the one to handle the final result. 36 00:02:14,240 --> 00:02:17,600 It should simply return the result of that computation. 37 00:02:17,600 --> 00:02:22,400 Whenever a function is performing a calculation or a computation of some sort. 38 00:02:22,490 --> 00:02:24,560 It should not handle the final result. 39 00:02:24,590 --> 00:02:31,010 It should just return the result and let whoever is calling the function to deal with that result as 40 00:02:31,010 --> 00:02:32,270 they see fit. 41 00:02:34,070 --> 00:02:38,530 But the function print area, its only task is to print the area. 42 00:02:38,540 --> 00:02:43,100 It's not performing any calculations, it's not performing any computations. 43 00:02:43,100 --> 00:02:45,880 So we cannot expect it to return any values. 44 00:02:45,890 --> 00:02:48,200 That's why it remains void. 45 00:02:48,230 --> 00:02:52,520 Void means the function does not return a value when called. 46 00:02:52,520 --> 00:02:56,810 It's simply going to print a message depending on what gets passed in. 47 00:02:56,810 --> 00:03:00,050 So what we're going to do is we're going to keep this simple. 48 00:03:00,080 --> 00:03:03,170 We're only going to call explain area once. 49 00:03:03,170 --> 00:03:06,200 We're only going to call calculate area once. 50 00:03:08,130 --> 00:03:14,100 When we calculate an area for the following length and width, we're going to print that area using 51 00:03:14,100 --> 00:03:15,570 the print area function. 52 00:03:15,570 --> 00:03:18,210 The first value that we pass in is the length. 53 00:03:18,990 --> 00:03:24,930 The second value that we pass in is the width, and the third value that we pass in is the area that 54 00:03:24,930 --> 00:03:27,540 was produced from the length and the width. 55 00:03:28,170 --> 00:03:32,040 And here we're just going to print the English explanation normally. 56 00:03:33,170 --> 00:03:33,890 All right. 57 00:03:33,890 --> 00:03:36,080 Putting breakpoints here, here and here. 58 00:03:36,080 --> 00:03:37,790 Re visualizing the runtime. 59 00:03:38,860 --> 00:03:46,390 So when you calculate an area for a length of 2.3 and a width of 3.6, you get a value of 8.28. 60 00:03:46,390 --> 00:03:54,160 And inside of the print area function, we're simply printing that a rectangle with a length of 2.3 61 00:03:54,160 --> 00:04:00,160 and a width of 3.6 has an area of 8.28. 62 00:04:00,280 --> 00:04:03,610 If I just simply continue to the next breakpoint. 63 00:04:04,590 --> 00:04:06,440 We're going to see that in our terminal. 64 00:04:07,580 --> 00:04:13,820 String English explanation is going to equal whatever the explain area function computes based on the 65 00:04:13,820 --> 00:04:15,230 language that was passed in. 66 00:04:15,230 --> 00:04:18,700 So the language that was passed in is English. 67 00:04:18,709 --> 00:04:22,670 We expect the explained area function to return the following text. 68 00:04:24,960 --> 00:04:26,520 That's exactly what it does. 69 00:04:26,550 --> 00:04:32,510 The English explanation variable stores, whatever the explain area function returns when we pass any 70 00:04:32,520 --> 00:04:33,610 value of English. 71 00:04:33,630 --> 00:04:36,120 And here we're just printing it. 72 00:04:38,350 --> 00:04:38,920 All right. 73 00:04:38,920 --> 00:04:45,160 The point I wanted to drive home was that when your function isn't performing any sort of computation 74 00:04:45,160 --> 00:04:51,040 or calculation, if it doesn't need to return anything of significance, then it needs to be void. 75 00:04:51,070 --> 00:04:55,330 Void means the function doesn't return anything when it performs its task. 76 00:04:55,330 --> 00:04:59,320 So when you're just printing something, there is really nothing to return. 77 00:04:59,320 --> 00:05:04,810 But when your function is performing some sort of calculation, some sort of computation that is needed 78 00:05:04,810 --> 00:05:10,180 to produce a final value, then you need to return that value from the function and then let whoever 79 00:05:10,180 --> 00:05:14,530 is calling the function to handle that value as they see fit.