1 00:00:00,540 --> 00:00:01,620 Hello and welcome. 2 00:00:01,620 --> 00:00:07,940 In this lecture we are going to look at the basic arithmetic operators. 3 00:00:07,940 --> 00:00:17,280 We're going to look at the precedence that has to be applied when you use multiple operators together. 4 00:00:17,510 --> 00:00:18,050 Okay. 5 00:00:18,060 --> 00:00:20,220 So I'm just going to modify the code a little bit. 6 00:00:20,250 --> 00:00:21,870 I'm going to get rid of this line. 7 00:00:21,870 --> 00:00:24,260 We don't need that anymore. 8 00:00:24,330 --> 00:00:34,170 And here are going to change this variable I to do multiple calculations. 9 00:00:34,170 --> 00:00:36,090 So let's get rid of that. 10 00:00:36,090 --> 00:00:38,910 So I'm going to do say seven 11 00:00:41,970 --> 00:00:46,080 plus maybe three 12 00:00:49,290 --> 00:00:50,270 times 13 00:00:54,170 --> 00:00:55,010 five. 14 00:00:57,560 --> 00:00:58,300 OK. 15 00:00:58,340 --> 00:01:00,220 There are no squiggly red lines. 16 00:01:00,240 --> 00:01:02,120 I mean it should be all right. 17 00:01:02,120 --> 00:01:07,190 Anytime you see the yellow bits it means you haven't saved your code. 18 00:01:07,190 --> 00:01:10,080 So I would just say that. 19 00:01:10,280 --> 00:01:18,170 So if we were to run this code what do you think the answer would be. 20 00:01:18,170 --> 00:01:21,740 It will definitely not be. 21 00:01:21,830 --> 00:01:27,830 You might think it's going to be five times three 15 plus seven. 22 00:01:27,830 --> 00:01:28,160 Right. 23 00:01:28,190 --> 00:01:32,550 You might think that way but we'd operators. 24 00:01:32,570 --> 00:01:34,970 There is a precedence. 25 00:01:35,030 --> 00:01:44,910 So what happens is that the multiplication and the division will occur before the addition and subtraction. 26 00:01:44,930 --> 00:01:45,410 All right. 27 00:01:45,770 --> 00:01:54,860 So if I run this code you see that you will do the three times five first before add in the seven and 28 00:01:54,860 --> 00:01:56,510 not the other way around. 29 00:01:56,510 --> 00:01:57,740 So let me executed. 30 00:01:57,740 --> 00:01:58,580 So you can see. 31 00:02:00,030 --> 00:02:02,450 So if I click and go you should see the output. 32 00:02:02,450 --> 00:02:10,270 So it's giving me twenty two so which is three times five is 15 plus 7. 33 00:02:10,280 --> 00:02:17,870 So it has done the multiplication first before going on to the addition. 34 00:02:17,870 --> 00:02:21,300 So let me stop running the code and click on that to stop it. 35 00:02:21,890 --> 00:02:31,660 If I wanted the addition to be calculated first I need to wrap it round inside parentheses. 36 00:02:31,670 --> 00:02:36,730 I need to do something like this. 37 00:02:37,330 --> 00:02:40,390 That's the only way C Sharp will do it first. 38 00:02:40,390 --> 00:02:42,410 So what C Sharp will not do. 39 00:02:42,640 --> 00:02:47,700 It will add this first so it will be the answer will not be ten times five. 40 00:02:47,740 --> 00:02:50,950 So I'll expect the output to be 50. 41 00:02:50,950 --> 00:02:52,060 So I've got that saved. 42 00:02:52,060 --> 00:02:54,360 Let's run the code again so we can see. 43 00:02:55,820 --> 00:02:56,450 OK. 44 00:02:56,470 --> 00:03:00,100 So if I click that I should expect an output of 50. 45 00:03:00,660 --> 00:03:01,060 All right. 46 00:03:01,060 --> 00:03:10,000 Because I have specifically put a parent this is around that which means it will now be done calculated 47 00:03:10,000 --> 00:03:22,570 first before the multiplication in this lecture we experimented with some operator precedents where 48 00:03:22,660 --> 00:03:34,030 we observed that by default multiplication and division will occur before addition and subtraction in 49 00:03:34,030 --> 00:03:36,380 order for us to make the addition. 50 00:03:36,980 --> 00:03:39,150 You know compute. 51 00:03:39,160 --> 00:03:44,600 First we have to wrap or place it inside parentheses. 52 00:03:44,650 --> 00:03:45,580 That's the only way. 53 00:03:45,580 --> 00:03:47,680 Takes precedence over. 54 00:03:47,680 --> 00:03:52,860 The higher operators like multiplication and division. 55 00:03:52,870 --> 00:03:59,650 So whenever you want a certain calculation type in certain ways and you're playing around with basic 56 00:03:59,650 --> 00:04:03,150 operators whichever one you want calculated first. 57 00:04:03,190 --> 00:04:07,870 You just need to place them inside parentheses and it will do that first. 58 00:04:08,200 --> 00:04:10,260 So that's it for this lecture. 59 00:04:10,270 --> 00:04:12,400 Thanks so much for watching. 60 00:04:12,400 --> 00:04:12,990 Bye for now.