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These are the user uploaded subtitles that are being translated: 1 00:00:01,080 --> 00:00:04,380 Hello everyone and welcome to the lecture on variables. 2 00:00:04,380 --> 00:00:09,990 This lecture we're going to go over some conventions on naming variables and how to assign the variables 3 00:00:10,080 --> 00:00:11,040 in R. 4 00:00:11,220 --> 00:00:13,710 Let's go ahead and jump to our studio. 5 00:00:13,710 --> 00:00:19,260 All right so here we are our studio and what I'm going to show you is just a couple of things that we're 6 00:00:19,260 --> 00:00:23,610 going to be learning as we begin our journey on learning the our programming language. 7 00:00:23,610 --> 00:00:27,030 And the first one we want to know is what actually comments or code. 8 00:00:27,270 --> 00:00:32,130 So what if you just want to leave yourself some notes either in your script or in the console. 9 00:00:32,130 --> 00:00:37,970 You can do is use a hash tag and this is similar to the Python programming language. 10 00:00:38,160 --> 00:00:44,070 And then whatever you write after the hash tag such as this is a comments. 11 00:00:44,130 --> 00:00:50,150 If you end up running this you'll notice that nothing comes out. 12 00:00:50,190 --> 00:00:53,040 So let's go ahead and show that in the console. 13 00:00:53,040 --> 00:01:03,540 So if I say something like print Hello enter and then if I were to do the exact same thing with a hash 14 00:01:03,540 --> 00:01:08,530 tag in front of it notice that I don't get any output because R won't read anything. 15 00:01:08,550 --> 00:01:11,510 Pass the hash tag because it treats it as just that comments. 16 00:01:11,520 --> 00:01:13,950 So that's one thing I want you to be aware of. 17 00:01:14,160 --> 00:01:20,460 And now let's go ahead and discuss variables and how to assign variables so variable names by convention 18 00:01:20,470 --> 00:01:20,900 . 19 00:01:21,120 --> 00:01:23,240 Start off with lower case letters. 20 00:01:23,520 --> 00:01:35,010 So if you had something like variable you would say use this assignment operator and then put in whatever 21 00:01:35,010 --> 00:01:37,410 you want to assign that variable. 22 00:01:37,440 --> 00:01:39,140 So what's actually happening here. 23 00:01:39,240 --> 00:01:40,560 We created a variable name. 24 00:01:40,560 --> 00:01:46,020 This case is called variable and we use the assignment operator which is this basically looks like an 25 00:01:46,020 --> 00:01:48,360 arrow which is nice for readability. 26 00:01:48,360 --> 00:01:52,860 So it's this less and and then a minus or a dash. 27 00:01:52,860 --> 00:01:58,440 So they form an arrow and then on the right hand side whatever data object or data type you want to 28 00:01:58,440 --> 00:01:59,520 assign to that very well. 29 00:01:59,520 --> 00:02:04,010 So for this lecturer it's going to be dealing with integers since that's something we've dealt with 30 00:02:04,020 --> 00:02:04,820 before. 31 00:02:05,130 --> 00:02:08,210 In the example of arithmetic. 32 00:02:08,460 --> 00:02:13,980 So here I am in signing the integer 100 to the variable called variable. 33 00:02:13,980 --> 00:02:20,910 So if I call variable again and then go ahead and just click enter in the council will return its assigned 34 00:02:20,910 --> 00:02:22,960 value which is 100. 35 00:02:22,980 --> 00:02:30,400 So let's go ahead and imagine another example will say bank and assignats 1000. 36 00:02:30,840 --> 00:02:35,050 So now if I call bank I get 1000 out as the assignments. 37 00:02:35,070 --> 00:02:37,500 So that's a variable assignment works. 38 00:02:37,560 --> 00:02:42,090 And you'll notice here in the environment if you ever want to know what variables you have or what values 39 00:02:42,090 --> 00:02:48,390 you have in your global environment for this session of Are You can reference this here. 40 00:02:48,390 --> 00:02:56,180 So just some quick style guides and convention points usually what you want to do is let's say you want 41 00:02:56,200 --> 00:02:59,340 to have multiple words in your variable name. 42 00:02:59,340 --> 00:03:04,290 What you would do is separate them by a period or dot. 43 00:03:04,440 --> 00:03:12,720 So we can say something like bank accounts and then assign that 100 so that's acceptable. 44 00:03:12,720 --> 00:03:20,250 Sometimes you also see this sort of notation bank and then instead of a dot They just write a capital 45 00:03:20,280 --> 00:03:22,560 A. 46 00:03:23,460 --> 00:03:31,240 What you won't see in our as often and is usually known as a bad style season. 47 00:03:31,290 --> 00:03:39,060 Underscore now it will still work completely So each of these is technically correct you can use all 48 00:03:39,060 --> 00:03:44,970 of these methods but the most common styles you'll see is this Fersen right here separating each of 49 00:03:44,970 --> 00:03:46,450 the words. 50 00:03:46,500 --> 00:03:48,390 All right. 51 00:03:48,390 --> 00:03:53,730 Later on when we discuss functions we'll go over the style guides for namea your functions and functions 52 00:03:53,730 --> 00:03:57,600 will actually usually start with capital letters. 53 00:03:57,600 --> 00:04:03,990 So finally just go ahead and show a quick simple example how you can use variables to perform calculations 54 00:04:04,050 --> 00:04:05,350 in operations that are. 55 00:04:05,460 --> 00:04:07,190 Let's go ahead and clear the cons.. 56 00:04:07,400 --> 00:04:12,690 And here in Windows I'm clearing the consulars by doing control L as a shortcut for that. 57 00:04:12,720 --> 00:04:19,550 So I'm just going to go ahead and say make a variable deposit assign it. 58 00:04:19,860 --> 00:04:22,040 Let's just say 20 enter. 59 00:04:22,050 --> 00:04:31,350 So I have my deposit and I'm going to say bank accounts bank account and I'm going to reassign bank 60 00:04:31,530 --> 00:04:37,820 accounts as my current bank account plus my deposit. 61 00:04:37,860 --> 00:04:44,220 So notice here before I actually run this line my bank account variable is equal to 100. 62 00:04:44,220 --> 00:04:47,580 My deposit is equal to 20 after running this line. 63 00:04:47,580 --> 00:04:54,720 What's going to happen by click enter my bank account is going to be equal to 120. 64 00:04:54,930 --> 00:05:01,530 So that's going to be the 20 plus the previous 100 value of bank account and it's going to update that 65 00:05:01,530 --> 00:05:06,810 variable which is bank accounts and that's the basic way you can use variables in a variable assignment 66 00:05:06,810 --> 00:05:07,740 operations. 67 00:05:07,820 --> 00:05:11,750 In our ok player I think it's pretty straightforward. 68 00:05:11,760 --> 00:05:18,000 The main thing to go to this lecture is that this symbol this arrow symbol is what you're going to be 69 00:05:18,000 --> 00:05:21,440 using for variable assignments in our. 70 00:05:21,780 --> 00:05:22,320 Okay. 71 00:05:22,380 --> 00:05:23,240 Thanks everyone. 72 00:05:23,250 --> 00:05:24,170 I'll see you at the next lecture 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