1 00:00:00,440 --> 00:00:05,100 All right, welcome back to Section three, lesson six operators. 2 00:00:05,120 --> 00:00:10,220 So today we're going to talk about how do you do operations in JavaScript? 3 00:00:10,340 --> 00:00:21,080 So operations are basically simple methods for doing mathematical expressions or logical expressions 4 00:00:21,560 --> 00:00:29,870 that can help us determine how something can be true or false or to change some value, mutate some 5 00:00:29,870 --> 00:00:34,580 number or some string into a different value. 6 00:00:34,820 --> 00:00:39,560 So that's called data mutation, where we're going to change the value from one number to another and 7 00:00:39,560 --> 00:00:43,410 we can use some basic mathematical expressions to do that. 8 00:00:44,330 --> 00:00:50,090 So there are many basic JavaScript operators that arithmetic assignment, comparison, logical and type 9 00:00:50,090 --> 00:00:52,300 of and there are others as well. 10 00:00:52,310 --> 00:00:55,520 So we're just going to start with those and look into them. 11 00:00:57,720 --> 00:01:01,490 OK, so those are the ones are going to take a look at it. 12 00:01:01,530 --> 00:01:05,060 So let's jump into examples. 13 00:01:06,360 --> 00:01:11,990 OK, so now we're in our JavaScript and let's just take a basic number, OK? 14 00:01:13,010 --> 00:01:17,660 Let's just take our basic number that we're going to declare and assign of count of zero. 15 00:01:18,650 --> 00:01:20,660 So what can we do with this count? 16 00:01:21,160 --> 00:01:24,170 OK, well, we can reassign it. 17 00:01:24,290 --> 00:01:26,210 We can set it equal to something else. 18 00:01:27,140 --> 00:01:36,380 And let's just go through the standard arithmetic operations so we can do count equals count plus one. 19 00:01:37,580 --> 00:01:41,740 We could also do count equals count minus one. 20 00:01:42,080 --> 00:01:46,420 And so that would be taking zero to one and then taking one back to zero. 21 00:01:47,210 --> 00:01:57,050 We can also do multiplication so we can times that by one we can do a division as well, divide by one 22 00:01:57,830 --> 00:01:59,210 and there are some others as well. 23 00:01:59,210 --> 00:02:00,290 We could do remainder. 24 00:02:00,630 --> 00:02:02,240 This is also called modulo. 25 00:02:02,840 --> 00:02:06,870 So we could do a remainder operation with this. 26 00:02:06,890 --> 00:02:12,070 So this would be if you divide by that number, then it will get you the remainder. 27 00:02:12,380 --> 00:02:14,990 So, you know, one divided by. 28 00:02:16,000 --> 00:02:21,520 To the remainder would still be zero or zero divided by two, the remainder would still be zero. 29 00:02:22,570 --> 00:02:27,150 OK, and then we can do increment. 30 00:02:27,520 --> 00:02:31,840 So if you want to do this, you could just do count plus plus. 31 00:02:31,840 --> 00:02:35,110 And that's going to be the same as count equals count plus one. 32 00:02:36,310 --> 00:02:37,660 You can actually do this. 33 00:02:37,660 --> 00:02:41,260 From the other perspective you could do plus plus count. 34 00:02:41,260 --> 00:02:43,390 There's a minor difference between those two. 35 00:02:44,170 --> 00:02:46,420 So count plus plus is going to add one to it. 36 00:02:46,420 --> 00:02:50,580 But technically this actually inside of a function return. 37 00:02:50,600 --> 00:02:52,570 So this is a very unique case. 38 00:02:53,020 --> 00:02:58,840 This is actually going to return, going to change the count up by one and then it's going to return 39 00:02:58,840 --> 00:03:00,670 the final value in this example. 40 00:03:00,670 --> 00:03:05,480 It actually returns the value and then it adds the one after it returns it. 41 00:03:05,510 --> 00:03:08,710 So you actually don't get the same return value in either case. 42 00:03:09,790 --> 00:03:12,310 OK, but both of these do count plus one. 43 00:03:12,310 --> 00:03:14,500 So they're the same functionally as this one right here. 44 00:03:14,960 --> 00:03:17,550 OK, all right. 45 00:03:17,560 --> 00:03:18,940 And then there are a few others. 46 00:03:18,940 --> 00:03:22,920 So we could do count equals minus count. 47 00:03:23,230 --> 00:03:26,230 So this would be get the negative of that option. 48 00:03:27,150 --> 00:03:27,560 OK. 49 00:03:28,110 --> 00:03:34,770 Oh, I guess corollary to this, you could do count minus, minus or minus minus count. 50 00:03:35,430 --> 00:03:40,920 OK, so that goes that does count minus one in the same exact way as this does count plus one. 51 00:03:41,190 --> 00:03:45,370 OK, you can also do exponents so we can do exponents. 52 00:03:45,370 --> 00:03:50,140 So if we do that does count to the power of. 53 00:03:50,160 --> 00:03:52,020 So we can do count to the power of two. 54 00:03:53,510 --> 00:03:59,240 OK, so these are the arithmetic operations I'm going to call this right here. 55 00:04:02,020 --> 00:04:03,100 Arithmetic 56 00:04:05,350 --> 00:04:08,770 operations, OK, operators. 57 00:04:11,330 --> 00:04:18,180 But there are many more than this, so let's take a look at comparison operators next day. 58 00:04:18,220 --> 00:04:24,650 So there are some comparison operators now with comparison operators, you're going to be doing some 59 00:04:25,130 --> 00:04:26,900 logical comparisons. 60 00:04:26,910 --> 00:04:32,150 You're going to find out whether something is the same as something else. 61 00:04:32,570 --> 00:04:39,110 OK, so this expression is going to resolve as either true or false. 62 00:04:40,160 --> 00:04:44,670 So you can see count equals zero. 63 00:04:44,990 --> 00:04:51,170 Now, this is going to be a check to see whether it is true or false. 64 00:04:51,350 --> 00:04:54,410 OK, and that's called a boolean value. 65 00:04:54,920 --> 00:04:55,180 OK. 66 00:04:55,250 --> 00:04:57,500 It's to find out whether it's a boolean value. 67 00:04:58,220 --> 00:05:01,250 You can do the same thing, but slightly different. 68 00:05:02,840 --> 00:05:04,490 Let's just copy the first part of this. 69 00:05:05,450 --> 00:05:10,400 You can do the same thing, but slightly different and say not equal to zero. 70 00:05:10,560 --> 00:05:14,960 And there's another actually sorry, this is only one exclamation. 71 00:05:14,990 --> 00:05:19,100 So the way that you do not equal to is exclamation equals zero. 72 00:05:20,560 --> 00:05:25,520 OK, and then there's a strict equal also called congruence. 73 00:05:25,670 --> 00:05:28,970 So you do count equals equals equals zero. 74 00:05:29,000 --> 00:05:35,720 So what this will do is it will check to see that their values are the same, not just the same, but 75 00:05:35,720 --> 00:05:38,590 there's also a sameness in the type. 76 00:05:38,720 --> 00:05:40,400 So they're the same data type. 77 00:05:41,150 --> 00:05:49,520 So that means if this was actually the string zero, so this would actually be a string like, you know, 78 00:05:49,520 --> 00:05:56,840 as you would have in a word, it would not actually be true that it would be district equal to zero. 79 00:05:57,140 --> 00:06:03,880 OK, you can do this, not equal, and that is with the exclamation equals. 80 00:06:04,760 --> 00:06:10,250 So in the case where you were to check whether they were the same data type, if they were not the same 81 00:06:10,250 --> 00:06:13,910 data type or the value was different, this would be seen as true. 82 00:06:14,120 --> 00:06:21,200 And then the next one is you're probably more familiar with count greater than zero and count less than 83 00:06:21,200 --> 00:06:21,590 zero. 84 00:06:22,430 --> 00:06:25,940 OK, and then there are a few more of those. 85 00:06:28,040 --> 00:06:37,400 So there's count greater than or equal to zero and there's count less than or equal to zero. 86 00:06:37,830 --> 00:06:44,810 OK, and obviously you can have any expression on the left side of this and any expression on the right 87 00:06:44,810 --> 00:06:45,500 side of this. 88 00:06:45,680 --> 00:06:48,410 OK, so it's a little bit simpler than simply an assignment. 89 00:06:49,010 --> 00:06:51,050 We're not assigning any values here. 90 00:06:51,050 --> 00:06:53,310 We're not mutating or changing any data. 91 00:06:53,930 --> 00:06:59,360 All we're doing is checking to see whether or not something a relationship between these two values 92 00:06:59,810 --> 00:07:01,140 is true or false. 93 00:07:01,430 --> 00:07:02,660 So that's the difference there. 94 00:07:03,910 --> 00:07:06,670 There are a lot of other types of operations we could do. 95 00:07:06,700 --> 00:07:11,500 I'm just going to show you a few others what are called the assignment operators. 96 00:07:12,760 --> 00:07:17,350 So these assignment operators can kind of shortcut some of the other things that we've been looking 97 00:07:17,350 --> 00:07:17,570 at. 98 00:07:18,340 --> 00:07:22,100 So first things, first count equals zero. 99 00:07:22,300 --> 00:07:28,610 That is our regular old assignment operator if we want to do an addition assignment. 100 00:07:28,840 --> 00:07:33,280 So that's combining the addition operator and the assignment operator. 101 00:07:34,060 --> 00:07:41,800 Then we can do count plus equals one or any other number, OK, or any other value. 102 00:07:41,890 --> 00:07:45,520 You could do this with strings and you could use this to concatenate strings together. 103 00:07:46,480 --> 00:07:48,010 So that's addition assignment. 104 00:07:48,040 --> 00:07:51,430 So this is the same as count equals count plus one. 105 00:07:52,900 --> 00:07:59,950 And then you can do a subtraction, you could do count minus equals and do the same thing as count equals 106 00:07:59,950 --> 00:08:02,340 count minus one, as you can see up on line five. 107 00:08:04,000 --> 00:08:09,910 And you can do multiplication assignment so you can count eight times equals. 108 00:08:12,850 --> 00:08:16,810 Let's just do that for differences and then you could do a division assignment. 109 00:08:17,230 --> 00:08:19,270 So you count divided equals 110 00:08:21,850 --> 00:08:24,550 and you can do the remainder assignment. 111 00:08:25,390 --> 00:08:27,730 So same thing right here. 112 00:08:30,940 --> 00:08:34,210 And count equals exponentiation assignment. 113 00:08:34,730 --> 00:08:37,090 So you can do just like that. 114 00:08:37,300 --> 00:08:42,940 So this is the same as count equals count to the power of some other number. 115 00:08:43,450 --> 00:08:43,810 OK. 116 00:08:46,560 --> 00:08:53,670 And there are also a number of others you can look at left shift assignment, bitwise logical assignment 117 00:08:53,670 --> 00:08:54,950 in a number of different things. 118 00:08:55,410 --> 00:09:03,630 So feel free to look at the resources for how you can use some of these other operations. 119 00:09:03,630 --> 00:09:07,690 But these are the ones that you're going to be using most of the time. 120 00:09:07,800 --> 00:09:12,000 There are a few other logical operators that I want to cover real quick. 121 00:09:14,020 --> 00:09:17,830 So these kind of go along with the comparison operators. 122 00:09:19,180 --> 00:09:24,780 You can just one thing you could do is just say our account is greater than zero. 123 00:09:25,510 --> 00:09:29,950 And so these are these are what's called logical operators. 124 00:09:31,060 --> 00:09:43,080 Logical operators count is greater than zero and count is greater than three. 125 00:09:43,480 --> 00:09:46,630 So that means they both have to be true at the same time. 126 00:09:46,840 --> 00:09:48,250 Or we could say less than three. 127 00:09:49,000 --> 00:09:52,120 So both have to be true at the same time for this to be the case. 128 00:09:53,590 --> 00:10:01,180 There's a very similar operation for not and but for so you could say or with the pipe key. 129 00:10:01,660 --> 00:10:07,540 And that is the one that's just to the left of the enter key, just above the right shift on the keyboard. 130 00:10:08,800 --> 00:10:12,730 And you have to you have to make sure you do you have to do a shift on that. 131 00:10:13,240 --> 00:10:18,340 OK, and this means or so you're saying, this one or the other one. 132 00:10:18,700 --> 00:10:24,010 OK, so either of these can be true and then this would result as true. 133 00:10:24,580 --> 00:10:28,560 OK, so those are the basic operators. 134 00:10:28,570 --> 00:10:30,790 There are a few others that you could learn. 135 00:10:31,300 --> 00:10:37,660 String operation is just you know, you can concatenate using the plus which is the addition operator 136 00:10:38,020 --> 00:10:46,290 and there are a few others as well, but that is it for the basics of JavaScript operators. 137 00:10:46,300 --> 00:10:47,980 And we'll see you in the next lesson.