WEBVTT 00:00.150 --> 00:05.340 Great to know, you know, how to use the milk and the micro functions to get the time since the beginning 00:05.340 --> 00:06.060 of the program. 00:06.450 --> 00:12.000 What am I going to do in this lesson is to learn how to compute the duration of an election. 00:12.270 --> 00:17.850 And this will help you for the next lesson where we actually solve the problem. 00:18.180 --> 00:23.670 OK, so commuting the duration of connection is very useful for mainly two things. 00:24.000 --> 00:29.600 So first, to solve the problem and also to be able to debug your program. 00:29.610 --> 00:36.660 So if you have an instruction that you think it's quite long and it's making your program lag, then 00:36.660 --> 00:41.820 you can easily check how long that instruction on that block of code takes. 00:42.030 --> 00:47.160 And then if you find out that it takes too long, you can improve your code. 00:47.460 --> 00:49.560 So let's make a quick example here. 00:50.220 --> 00:51.780 I'm going to remove all that. 00:52.110 --> 00:55.860 And the action I'm going to measure is simply a delay. 00:56.730 --> 00:57.570 Let's say delay. 00:57.570 --> 00:58.230 Five hundred. 00:58.890 --> 01:04.830 But this is convenient, for the example, because we know that the DeLay 500 will take five hundred 01:04.830 --> 01:05.440 milliseconds. 01:05.460 --> 01:12.450 OK, so this way we can validate that our program to compute the duration of connection works and then 01:12.450 --> 01:14.040 we can use that on any of them. 01:14.040 --> 01:14.640 Look of code. 01:14.880 --> 01:22.020 So if you want to measure the duration between the line four and line six of the program here, what 01:22.020 --> 01:31.410 you would need to do is first to get the time before the action and then do the action and then get 01:31.410 --> 01:37.800 the time after the action and then simply make the difference between the time after the action and 01:37.800 --> 01:40.740 the time before the action and you get the duration. 01:40.770 --> 01:41.130 All right. 01:41.140 --> 01:47.130 So let's let's simply right the code for that unsigned long time. 01:47.140 --> 01:47.970 I'm going to name it. 01:47.970 --> 01:48.960 Time begin. 01:50.950 --> 01:52.000 We miss. 01:53.540 --> 02:01.460 So here we get in the time being viable, the time just before we execute the action, now we execute 02:01.460 --> 02:06.410 the action and signed long time and. 02:08.510 --> 02:10.410 OK, so that is the exact same thing. 02:10.430 --> 02:16.580 OK, we just use a different label, so here we have the time before the action, we do the action. 02:16.610 --> 02:18.720 We started time after the action. 02:18.820 --> 02:21.770 OK, so it's important to get the time before the action. 02:21.940 --> 02:24.140 OK, so we can compare the two here. 02:24.450 --> 02:30.970 OK, the minutes here will give a different result than the minutes here because 500 milliseconds have 02:30.980 --> 02:35.000 passed in the prior and not to compute the duration. 02:35.000 --> 02:39.300 So the duration will be the time and minus the time being. 02:39.890 --> 02:43.690 OK, the duration will always be positive. 02:44.150 --> 02:51.620 So if it's always positive, I'm going to use unsigned also long duration and then we simply make the 02:51.620 --> 02:55.440 substraction time and minus time. 02:56.510 --> 03:01.340 OK, in this order and we get the duration of the action. 03:01.490 --> 03:02.000 Great. 03:02.600 --> 03:08.300 Let's simply make sure that L.N. duration. 03:10.210 --> 03:16.360 What I could do to make it nicer is maybe to do, say, under Prince the. 03:18.300 --> 03:19.680 Duration is. 03:21.840 --> 03:26.670 Ladies, and then they'll bring and with duration. 03:27.180 --> 03:31.600 So here the duration will be on the same line as the duration is. 03:31.920 --> 03:38.490 And after that, within the next day, Prince William will go to annealing and let's try this. 03:38.490 --> 03:38.830 Cool. 03:38.910 --> 03:43.370 So I'm going to code, must say, a monitor. 03:45.290 --> 03:52.010 The duration is four hundred ninety nine, which is already close to 500, so great with this goal, 03:52.370 --> 03:56.870 you can get the duration of any action of any block of code. 03:57.680 --> 04:04.460 Now, you can also use macros like Westing we've seen before, the micros. 04:05.430 --> 04:12.360 Microsoft, so microbes also stored on unsign long, so you can just keep eating them like this going 04:12.390 --> 04:16.710 to upload and you will see now the duration is. 04:18.170 --> 04:28.220 Five, we so 500000, which is also 500 milliseconds, which exactly is what we have in the delay here. 04:29.030 --> 04:33.060 OK, so if you want more precision, you can use Migros, OK? 04:33.200 --> 04:37.820 If you don't want to be more precise than one milliseconds, you can use Milice. 04:42.480 --> 04:48.400 And in these schools, mostly, I will use Ministroke because we don't need to be super extra precise. 04:48.420 --> 04:50.340 OK, one minute is already quite quick. 04:51.000 --> 04:51.350 All right. 04:51.360 --> 04:57.360 So that is the way to get the duration of what action you measure the time before you do the action. 04:57.360 --> 04:58.850 You measure the time after. 04:59.340 --> 05:03.340 Then you get the duration by subtracting the two times. 05:03.360 --> 05:08.950 You can make sure that you when you measure the time is just before and just after the action. 05:08.970 --> 05:10.890 OK, just don't do anything else. 05:10.890 --> 05:12.450 Like don't bring something. 05:12.780 --> 05:14.600 Just measure the action you want to measure. 05:15.300 --> 05:17.420 And I'm going to show you something a little bit different. 05:17.460 --> 05:23.430 OK, so you can actually still get the duration in the loop function from something that you have initialized 05:23.430 --> 05:26.710 outside of the function that just doing simple. 05:26.730 --> 05:27.550 So you can understand. 05:28.500 --> 05:31.560 So I'm going to write here and sign. 05:32.740 --> 05:33.190 Long. 05:34.140 --> 05:35.370 Thank you. 05:37.510 --> 05:46.980 So I just declare Dimebolin, I don't initialize it, let's write this, let's actually commend it, 05:47.710 --> 05:48.550 we don't need that. 05:49.510 --> 05:55.210 He insulated the cell communication they do time biggin equal to. 05:55.460 --> 06:01.270 Maybe I could just have initialised images here that would be the same because Millet's would be zero 06:01.270 --> 06:01.840 at the beginning. 06:01.840 --> 06:04.570 OK, and not in the loop I'm going to do. 06:05.960 --> 06:12.170 DeLay one thousand and then and sign long. 06:13.240 --> 06:23.560 Time now is equal to me, so every time I get the time in the loop and then let's say unsigned, long 06:23.800 --> 06:24.580 duration. 06:26.200 --> 06:31.600 Things start is equal to time now minus. 06:32.700 --> 06:39.390 I'm mean, and then a prince say that print and then we duration. 06:43.510 --> 06:45.380 But what I'm what am I doing here? 06:45.850 --> 06:52.150 There is a time that we have initialised, OK, this is a global variable, so it has been initialized 06:52.150 --> 06:53.020 to some value. 06:53.030 --> 06:55.630 So here, for example, zero and then in the loop. 06:55.640 --> 06:59.530 So I do my action in the loop, which takes one second, for example. 07:00.130 --> 07:07.090 And then I measure the time and I measure the duration between the time now in the loop nine, the time 07:07.090 --> 07:07.430 being. 07:07.450 --> 07:14.740 So we get here, we can get the duration also since a certain point of time that we have initialized 07:15.100 --> 07:16.150 outside of the loop. 07:17.570 --> 07:18.590 So let's just bring. 07:20.060 --> 07:21.320 Is just the way does. 07:23.220 --> 07:28.400 And you can see we have one, two, three, four, five thousand, etc..