1 00:00:02,080 --> 00:00:07,420 So another type of data types. 2 00:00:08,560 --> 00:00:23,650 And that you can see is signed and unsigned now, signed variables can be either positive or negative 3 00:00:23,950 --> 00:00:28,370 because they have one bit reserved for design. 4 00:00:28,390 --> 00:00:35,980 So one of the bids out of the entire structure will be reserved for sign is the most significant bit, 5 00:00:35,980 --> 00:00:37,660 and I'll show you later on. 6 00:00:38,740 --> 00:00:48,760 But an unsigned data type, an unsigned variable, does not have a sign, so therefore the value that 7 00:00:48,760 --> 00:00:51,880 gets stored in it is always positive. 8 00:00:53,500 --> 00:00:58,960 Now, the next data type that we're going to talk about is character. 9 00:01:00,280 --> 00:01:04,690 The character data type will store only individual characters. 10 00:01:04,870 --> 00:01:13,720 When assigning a value to a char variable, you must use single quotes around the character like this. 11 00:01:15,190 --> 00:01:19,150 And the charged data type is still a numeric type. 12 00:01:19,870 --> 00:01:27,790 That means that each character will actually be stored in the computer memory as a number. 13 00:01:28,150 --> 00:01:33,850 The key word for the character data type is char or care. 14 00:01:34,060 --> 00:01:35,560 However you want to call it. 15 00:01:36,040 --> 00:01:42,730 And here you can see how the characters get mapped to the numbers. 16 00:01:43,060 --> 00:01:45,160 And this is the ASCII table. 17 00:01:45,490 --> 00:01:53,110 ASCII stands for American Standard Code for information exchange, and what you want to look for is 18 00:01:53,110 --> 00:01:55,450 the decimal value here. 19 00:01:55,720 --> 00:02:05,260 So if you want to know what lowercase C is in decimal, it's right here. 20 00:02:05,260 --> 00:02:06,520 It's ninety nine. 21 00:02:12,090 --> 00:02:24,300 So for the character data type, we have unsigned and signed versions, so for unsigned char, this 22 00:02:24,300 --> 00:02:27,300 is going to be the key word for it. 23 00:02:27,860 --> 00:02:32,490 And this will also hold only one character at a time. 24 00:02:32,790 --> 00:02:37,680 But it does occupy one bite on most computer systems. 25 00:02:38,760 --> 00:02:50,400 And one by means a bit, so you can see here the lowest value that an unsigned char variable can hold 26 00:02:50,760 --> 00:02:58,950 is all zeros because it doesn't have a sign, all of the bits are used for value. 27 00:02:59,850 --> 00:03:05,040 And then the maximum is when all of the bids are won. 28 00:03:07,820 --> 00:03:14,780 And here you can see the range, it ranges between zero and 255 inclusively. 29 00:03:15,170 --> 00:03:20,540 So for signs, character data type. 30 00:03:20,780 --> 00:03:30,020 This one has a sign and like I was saying before, the most significant bit is used to represent the 31 00:03:30,020 --> 00:03:30,680 sign. 32 00:03:31,040 --> 00:03:35,410 Now, the minimum actually this. 33 00:03:35,420 --> 00:03:38,990 So this also occupies one bite in the computer memory. 34 00:03:39,200 --> 00:03:42,380 So eight bits you have them represented here. 35 00:03:42,650 --> 00:03:50,330 And because this has a sign, one means minus zero means plus. 36 00:03:50,690 --> 00:04:01,130 So the least number that these bits can represent, together with this being a minus is the maximum 37 00:04:01,130 --> 00:04:02,330 of the value. 38 00:04:03,380 --> 00:04:11,720 So all of these value bits will be set to one that yields minus 128. 39 00:04:12,200 --> 00:04:18,860 And then the maximum value in this case, the sign will be plus. 40 00:04:19,190 --> 00:04:28,700 And then the maximum of these like value bits, which are still one, and that will be one twenty seven. 41 00:04:28,910 --> 00:04:41,300 So that is the range and the the way to know if your char is signed is that there's no one sign in front 42 00:04:41,300 --> 00:04:41,960 of it here. 43 00:04:43,740 --> 00:04:44,430 So. 44 00:04:48,820 --> 00:04:52,870 Another data type very important is an integer. 45 00:04:53,110 --> 00:05:04,390 So the integer can only hold hold numbers and unsigned integers will only hold a positive whole number. 46 00:05:04,930 --> 00:05:12,040 Meanwhile, signed integers can hold either a positive whole number or a negative one. 47 00:05:13,300 --> 00:05:24,640 So here you can see that the unsigned integer occupies four bytes in computer memory now. 48 00:05:24,640 --> 00:05:28,630 So that is 32 bits and you can see it here. 49 00:05:30,310 --> 00:05:36,970 In the case that we're talking about the minimum value that an unsigned end can have. 50 00:05:37,450 --> 00:05:46,270 It is all zeros because there is no sign and all of the 32 bits are used for value. 51 00:05:47,170 --> 00:05:57,010 So in this case, zero is the lowest value in the range that an unsigned in can hold now for the maximum, 52 00:05:57,010 --> 00:06:00,430 and they're going to be all one, and that yields four million. 53 00:06:00,580 --> 00:06:08,380 Now four million two hundred ninety four million nine hundred sixty seven thousand two hundred ninety 54 00:06:08,380 --> 00:06:08,830 five. 55 00:06:09,400 --> 00:06:12,100 So this is the range. 56 00:06:13,840 --> 00:06:17,210 And unsigned and is the key word for it. 57 00:06:17,560 --> 00:06:28,900 And this unsigned INT data type can only hold all numbers in between this range right here. 58 00:06:29,590 --> 00:06:33,130 No more and no negatives, for sure. 59 00:06:33,490 --> 00:06:40,900 And here is an example if you want to create a variable of type unsigned int. 60 00:06:42,130 --> 00:06:43,420 This is how you do it. 61 00:06:44,660 --> 00:06:50,540 So far, it is signed, and now this one does have a sign. 62 00:06:50,900 --> 00:07:00,920 And the most significant bit here will be the sign in the case of the minimum, because this also has 63 00:07:00,920 --> 00:07:03,440 four bites, so this will be thirty two bids. 64 00:07:05,180 --> 00:07:14,360 In the case of the minimum, this sign will be a minus and then we want the maximum value of the rest 65 00:07:14,360 --> 00:07:20,090 of the bids, which actually are going to be all used for value, except for this one. 66 00:07:20,930 --> 00:07:23,930 And that will be this number here. 67 00:07:25,180 --> 00:07:31,840 And then for the maximum, we want a plus and then the maximum value we can get out of the rest of the 68 00:07:31,840 --> 00:07:38,860 bits which are used for value, so that yields to this number here. 69 00:07:40,030 --> 00:07:43,720 And the key word for assigned integer is int. 70 00:07:44,260 --> 00:07:50,800 And this is an example of how you can create a variable of type signed end. 71 00:07:51,880 --> 00:07:57,130 So another data type that I want to talk about is a float. 72 00:07:57,490 --> 00:08:06,130 So a float is used to define variables that can hold real numbers of fractions, right? 73 00:08:07,930 --> 00:08:14,950 Float is considered single precision because it can hold up to seven decimal places. 74 00:08:15,160 --> 00:08:18,580 It still has a size of four bytes. 75 00:08:18,910 --> 00:08:22,480 And this is the key word for it float. 76 00:08:23,200 --> 00:08:24,520 Here's an example. 77 00:08:25,940 --> 00:08:33,470 So you'll be using this if you need to store a number that has maximum seven decimal places. 78 00:08:34,910 --> 00:08:42,320 Otherwise, the rest of them will just not be stored if it has, let's say, eight. 79 00:08:43,350 --> 00:08:50,940 Decimal places, the number that you're trying to store, it will just be like rounded up or down, 80 00:08:50,940 --> 00:08:58,110 depending on if it's five or under or five or more. 81 00:08:59,310 --> 00:09:10,080 And one very important thing to mention about floating a float is that there are no unsigned floating 82 00:09:10,080 --> 00:09:16,050 point data types so it can hold either negative or positive numbers. 83 00:09:17,430 --> 00:09:26,700 And double is like floats bigger brother because it basically does the whole thing, but it does have 84 00:09:26,700 --> 00:09:27,930 double precision. 85 00:09:28,230 --> 00:09:37,470 So that means that it can hold up to 15 decimal places and it has a size of eight bytes, so it's double 86 00:09:37,470 --> 00:09:38,370 in size. 87 00:09:38,640 --> 00:09:40,500 Key word for this is double. 88 00:09:40,740 --> 00:09:52,170 So one thing to to keep in mind here, too, is that there are no unsigned floating point data types 89 00:09:52,800 --> 00:09:53,820 like for a float. 90 00:09:54,240 --> 00:09:58,040 And this is still considered a floating point data type. 91 00:09:58,050 --> 00:10:06,360 So double and float definitely are kind of the same thing, but more precision and one less another. 92 00:10:06,750 --> 00:10:16,230 Now, with that being said, we've talked about a lot of things in this lecture, but take it all with 93 00:10:16,230 --> 00:10:24,660 a grain of salt just because the sizes and ranges may be different on your operating system. 94 00:10:24,960 --> 00:10:36,150 The all of the sizes that we've talked about it are actually only specific to most operating systems, 95 00:10:36,660 --> 00:10:37,500 so. 96 00:10:39,120 --> 00:10:49,230 What you can do to actually find your design is that your variables or your data types occupy on your 97 00:10:49,230 --> 00:10:58,650 computer system is to use the C plus plus size of operator to find the size that a variable occupies 98 00:10:58,650 --> 00:10:59,490 in memory. 99 00:10:59,850 --> 00:11:10,260 So, for example, if we have an INT variable called value that we assign tend to here doesn't even 100 00:11:10,260 --> 00:11:14,340 matter if we've assigned a value to it yet or not. 101 00:11:14,340 --> 00:11:23,730 If the variable is defined, we can use this statement see out size of value to print the number of 102 00:11:23,730 --> 00:11:27,930 bytes, then the variable occupies in memory so. 103 00:11:29,420 --> 00:11:35,180 Hopefully, you had a lot of fun watching this, this lecture. 104 00:11:35,300 --> 00:11:40,970 We did talk about quite a few things today, so let us know if you have any questions. 105 00:11:42,200 --> 00:11:43,970 And see you in the next lecture.