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These are the user uploaded subtitles that are being translated: 1 1 00:00:01,150 --> 00:00:04,280 Let's now meet one of the primitive data types, 2 2 00:00:04,280 --> 00:00:06,550 that we never talked about before 3 3 00:00:06,550 --> 00:00:07,827 and that is BigInt. 4 4 00:00:08,930 --> 00:00:12,300 So big and is a special type of integers 5 5 00:00:12,300 --> 00:00:15,320 that was introduced in year 2020 6 6 00:00:15,320 --> 00:00:17,533 and so let's quickly take a look at it. 7 7 00:00:19,090 --> 00:00:22,030 So we learned in the first lecture of the section 8 8 00:00:22,030 --> 00:00:26,900 that numbers are represented internally as 64 bits. 9 9 00:00:26,900 --> 00:00:31,900 And that means that there are exactly 64 ones or zeros 10 10 00:00:32,240 --> 00:00:34,720 to represent any given number. 11 11 00:00:34,720 --> 00:00:38,910 Now of these 64 bits only 53 are used 12 12 00:00:38,910 --> 00:00:41,730 to actually store the digits themselves. 13 13 00:00:41,730 --> 00:00:43,760 The rest are for storing the position 14 14 00:00:43,760 --> 00:00:46,850 of the decimal point and the sign. 15 15 00:00:46,850 --> 00:00:51,030 Now, if there are only 53 bits to store the number, 16 16 00:00:51,030 --> 00:00:52,830 that means that there is a limit 17 17 00:00:52,830 --> 00:00:55,310 of how big numbers can be, 18 18 00:00:55,310 --> 00:00:57,630 and we can calculate that number. 19 19 00:00:57,630 --> 00:01:02,330 So that's two elevated to 53 20 20 00:01:03,550 --> 00:01:08,463 and then minus one, because the numbers starts at zero. 21 21 00:01:09,560 --> 00:01:13,220 And so that is this gigantic number right here. 22 22 00:01:13,220 --> 00:01:16,220 And so this is essentially the biggest number 23 23 00:01:16,220 --> 00:01:21,220 that JavaScript can safely represent, okay. 24 24 00:01:22,110 --> 00:01:23,573 Or actually is 53. 25 25 00:01:25,020 --> 00:01:28,550 So this is the biggest number, alright. 26 26 00:01:28,550 --> 00:01:29,590 And it is two, 27 27 00:01:29,590 --> 00:01:32,680 because again we are working with base two, 28 28 00:01:32,680 --> 00:01:34,703 which has only zeros and ones. 29 29 00:01:35,650 --> 00:01:37,380 And this number is so important 30 30 00:01:37,380 --> 00:01:40,750 that it's even stored into the number namespace 31 31 00:01:41,650 --> 00:01:42,650 as MAX_SAFE_INTEGER. 32 32 00:01:46,120 --> 00:01:49,170 So this gives us the exact same number. 33 33 00:01:49,170 --> 00:01:50,320 Now right? 34 34 00:01:50,320 --> 00:01:54,370 So any integer that is larger than this, is not safe 35 35 00:01:54,370 --> 00:01:58,760 and that means it cannot be represented accurately. 36 36 00:01:58,760 --> 00:02:00,870 So let's duplicate this line here 37 37 00:02:00,870 --> 00:02:03,543 and for example add one to this. 38 38 00:02:04,827 --> 00:02:08,870 And so you'll see that this is not correct, right? 39 39 00:02:08,870 --> 00:02:10,300 It only added one number 40 40 00:02:10,300 --> 00:02:13,263 to this one where it should have been added two. 41 41 00:02:14,400 --> 00:02:17,613 So if we do this, then we get the exact same thing. 42 42 00:02:18,480 --> 00:02:20,410 So we keep adding numbers here 43 43 00:02:20,410 --> 00:02:22,820 and they are always the same. 44 44 00:02:22,820 --> 00:02:24,890 And so that means that JavaScript can 45 45 00:02:24,890 --> 00:02:28,330 simply not represent these numbers accurately. 46 46 00:02:28,330 --> 00:02:31,280 And so if we do calculations with numbers 47 47 00:02:31,280 --> 00:02:32,130 that are bigger than this, 48 48 00:02:32,130 --> 00:02:36,310 then we might lose precision, okay. 49 49 00:02:36,310 --> 00:02:39,790 So in some numbers it does actually work 50 50 00:02:39,790 --> 00:02:42,550 for some reason, but that's because JavaScript 51 51 00:02:42,550 --> 00:02:45,090 behind the scenes uses some tricks 52 52 00:02:45,090 --> 00:02:48,540 to still represent some of the unsafe numbers. 53 53 00:02:48,540 --> 00:02:51,470 But again, sometimes that works, 54 54 00:02:51,470 --> 00:02:53,090 sometimes it doesn't. 55 55 00:02:53,090 --> 00:02:55,783 And so that's why we call these unsafe numbers. 56 56 00:02:57,010 --> 00:03:01,060 So you'll see sometimes these numbers are 57 57 00:03:01,060 --> 00:03:03,170 or at least look correct. 58 58 00:03:03,170 --> 00:03:06,193 And sometimes they don't, okay. 59 59 00:03:07,410 --> 00:03:10,200 So, this can be a problem sometimes 60 60 00:03:10,200 --> 00:03:11,890 because in some situations 61 61 00:03:11,890 --> 00:03:14,960 we might need really, really big numbers. 62 62 00:03:14,960 --> 00:03:16,750 Way bigger than this one here, 63 63 00:03:16,750 --> 00:03:19,860 for example, for database IDs 64 64 00:03:19,860 --> 00:03:23,460 or when interacting with real 60 bit numbers 65 65 00:03:23,460 --> 00:03:27,050 and these numbers are actually used in other languages. 66 66 00:03:27,050 --> 00:03:28,470 And so we might, for example 67 67 00:03:28,470 --> 00:03:31,910 from some API, get a number that is larger than this. 68 68 00:03:31,910 --> 00:03:34,040 And then we have no way 69 69 00:03:34,040 --> 00:03:36,990 of storing that in JavaScript, 70 70 00:03:36,990 --> 00:03:39,060 at least not until now, 71 71 00:03:39,060 --> 00:03:42,170 because now starting from IES 2020 72 72 00:03:42,170 --> 00:03:44,270 a new primitive was added, 73 73 00:03:44,270 --> 00:03:46,520 which is called BigInt. 74 74 00:03:46,520 --> 00:03:50,660 Now right? And BigInt stands for big integer. 75 75 00:03:50,660 --> 00:03:55,090 And it can be used to store numbers as large as we want. 76 76 00:03:55,090 --> 00:03:58,460 So no matter how big, all right. 77 77 00:03:58,460 --> 00:04:00,750 So let's say we need this number 78 78 00:04:00,750 --> 00:04:04,130 and I'm just using random numbers here. 79 79 00:04:04,130 --> 00:04:05,453 So if I lock this, 80 80 00:04:06,370 --> 00:04:09,488 then you'll see well this here 81 81 00:04:09,488 --> 00:04:12,200 which probably does not have precision 82 82 00:04:12,200 --> 00:04:14,850 because of course it's larger than this, 83 83 00:04:14,850 --> 00:04:19,850 but if I use the n, then this will be a BigInt. 84 84 00:04:19,862 --> 00:04:21,852 So let's see that. 85 85 00:04:21,852 --> 00:04:26,852 And so this n here basically transforms a regular number, 86 86 00:04:27,000 --> 00:04:29,350 into a BigInt number. 87 87 00:04:29,350 --> 00:04:30,750 And you see in the console here, 88 88 00:04:30,750 --> 00:04:34,498 it then also does look different. Okay? 89 89 00:04:34,498 --> 00:04:37,890 So this is a really really huge number, 90 90 00:04:37,890 --> 00:04:40,040 but now JavaScript has a way 91 91 00:04:40,040 --> 00:04:43,880 of finally displaying this number here accurately. 92 92 00:04:43,880 --> 00:04:45,260 All right. 93 93 00:04:45,260 --> 00:04:49,253 We can also create BigInt by using the BigInt function. 94 94 00:04:52,440 --> 00:04:54,580 So sometimes that's necessary 95 95 00:04:54,580 --> 00:04:56,203 and then without the n. 96 96 00:04:57,340 --> 00:05:00,230 And so this gives us kind of the same result, 97 97 00:05:00,230 --> 00:05:02,630 while not really, for some reason, 98 98 00:05:02,630 --> 00:05:06,240 but I guess it is because JavaScript will first have 99 99 00:05:06,240 --> 00:05:09,490 to still represent this number here internally, 100 100 00:05:09,490 --> 00:05:12,970 before it can then transform it into a BigInt. 101 101 00:05:12,970 --> 00:05:14,890 And that's the reason why here 102 102 00:05:14,890 --> 00:05:18,173 from a certain point on this second number is different. 103 103 00:05:19,260 --> 00:05:23,000 So this constructor function should probably only be used 104 104 00:05:23,000 --> 00:05:24,603 with small numbers, 105 105 00:05:25,840 --> 00:05:27,273 for example, like this. 106 106 00:05:28,820 --> 00:05:29,653 Now, okay. 107 107 00:05:29,653 --> 00:05:32,440 So this is how we create BigInt numbers 108 108 00:05:33,620 --> 00:05:37,410 but let's now see some operations with these numbers. 109 109 00:05:37,410 --> 00:05:40,790 And well, basically it's very simple. 110 110 00:05:40,790 --> 00:05:44,280 All the usual operators still work the same. 111 111 00:05:44,280 --> 00:05:49,280 So let's say we have one or 10,000n plus 10,000 again. 112 112 00:05:51,820 --> 00:05:52,653 And so in this case 113 113 00:05:52,653 --> 00:05:55,990 of course we wouldn't even need a BigInt, 114 114 00:05:55,990 --> 00:05:57,750 but this is just to demonstrate 115 115 00:05:57,750 --> 00:06:01,900 that the operators work just the same with BigInt. 116 116 00:06:01,900 --> 00:06:04,250 So we get indeed 20,000 117 117 00:06:05,450 --> 00:06:08,670 and the same is true with other operations. 118 118 00:06:08,670 --> 00:06:10,920 So for example, a multiplication, 119 119 00:06:10,920 --> 00:06:12,890 let's try a really huge number 120 120 00:06:16,210 --> 00:06:19,660 10 times this and a huge number. 121 121 00:06:19,660 --> 00:06:22,353 And so it then gives us, this result. 122 122 00:06:23,250 --> 00:06:25,410 Now what is not possible is 123 123 00:06:25,410 --> 00:06:28,433 to mix BigInt with regular numbers. 124 124 00:06:29,820 --> 00:06:32,423 So let's say we have huge, 125 125 00:06:33,780 --> 00:06:36,443 so some random number like this. 126 126 00:06:38,034 --> 00:06:41,673 And then we have a regular number, which is just 23. 127 127 00:06:44,990 --> 00:06:47,720 And so if I wanted to multiply them 128 128 00:06:47,720 --> 00:06:52,720 so huge times num then we would get this error 129 129 00:06:53,420 --> 00:06:56,073 cannot mix BigInt and other types. 130 130 00:06:57,370 --> 00:06:58,260 All right? 131 131 00:06:58,260 --> 00:06:59,850 And so this is where we then would have 132 132 00:06:59,850 --> 00:07:03,610 to convert this number here to a BigInt. 133 133 00:07:03,610 --> 00:07:06,419 And this is where the constructor function 134 134 00:07:06,419 --> 00:07:09,413 that i showed you here becomes necessary. 135 135 00:07:13,394 --> 00:07:16,650 And so now it is indeed going to work. 136 136 00:07:16,650 --> 00:07:19,490 However, there are two exceptions to this 137 137 00:07:19,490 --> 00:07:21,920 which are the comparison operators 138 138 00:07:21,920 --> 00:07:25,760 and the plus operator when working with strings. 139 139 00:07:25,760 --> 00:07:27,349 So let's see that. 140 140 00:07:27,349 --> 00:07:30,664 So we can still do a BigInt, 141 141 00:07:30,664 --> 00:07:34,609 and then for example, a greater than a normal number. 142 142 00:07:34,609 --> 00:07:36,350 So this still works 143 143 00:07:36,350 --> 00:07:40,103 and we still get true as expected, okay. 144 144 00:07:41,230 --> 00:07:42,950 However, when we do this 145 145 00:07:42,950 --> 00:07:47,170 so 20n equal, equal, equal 20, 146 146 00:07:47,170 --> 00:07:48,960 we will get false. 147 147 00:07:48,960 --> 00:07:50,250 But that makes sense 148 148 00:07:50,250 --> 00:07:53,310 because JavaScript when we use the triple operator 149 149 00:07:53,310 --> 00:07:55,640 does not do type coercion. 150 150 00:07:55,640 --> 00:07:56,800 And in fact, 151 151 00:07:56,800 --> 00:07:58,140 these two values here, 152 152 00:07:58,140 --> 00:08:00,710 they have a different primitive type. 153 153 00:08:00,710 --> 00:08:04,293 This is a regular number, and this is a BigInt. 154 154 00:08:05,350 --> 00:08:06,700 In fact, we can check that, 155 155 00:08:09,160 --> 00:08:11,760 Or at least I think we can, 156 156 00:08:11,760 --> 00:08:13,173 I never did this actually. 157 157 00:08:14,740 --> 00:08:18,547 But yeah, indeed the type of this is a BigInt, 158 158 00:08:19,640 --> 00:08:21,000 All right. 159 159 00:08:21,000 --> 00:08:25,930 But however, if we do the regular equality operator, 160 160 00:08:25,930 --> 00:08:27,063 so the lose one, 161 161 00:08:28,610 --> 00:08:30,313 then this should still be true. 162 162 00:08:31,410 --> 00:08:35,390 Right. Because then JavaScript does the type coercion. 163 163 00:08:35,390 --> 00:08:38,750 And so then it will coerce this one to a regular number, 164 164 00:08:38,750 --> 00:08:41,050 and then they're both the same. 165 165 00:08:41,050 --> 00:08:44,903 So just like, so it would even work like this. 166 166 00:08:46,360 --> 00:08:49,923 So this is one exception that's right out here. 167 167 00:08:53,010 --> 00:08:55,350 So logical operators are one exception. 168 168 00:08:55,350 --> 00:08:57,780 And the other exception is when 169 169 00:08:57,780 --> 00:09:01,370 we do string concatenations. 170 170 00:09:01,370 --> 00:09:05,240 So let's say huge plus 171 171 00:09:06,440 --> 00:09:08,180 and then some string here, 172 172 00:09:08,180 --> 00:09:12,393 is really big. 173 173 00:09:13,810 --> 00:09:16,300 Now. And so you'll see in this case, 174 174 00:09:16,300 --> 00:09:19,560 the number isn't actually converted to a string. 175 175 00:09:19,560 --> 00:09:23,190 So even the BigInt number, okay. 176 176 00:09:23,190 --> 00:09:27,080 Now, one other thing that I didn't tell you up here is 177 177 00:09:27,080 --> 00:09:30,050 that also the math operations that we talked 178 178 00:09:30,050 --> 00:09:32,493 about earlier are not gonna work here. 179 179 00:09:33,750 --> 00:09:37,683 For example, we cannot take this square root like this. 180 180 00:09:38,740 --> 00:09:41,723 Q R T of 16n. 181 181 00:09:44,100 --> 00:09:45,200 All right. 182 182 00:09:45,200 --> 00:09:46,593 So that doesn't work. 183 183 00:09:50,000 --> 00:09:51,320 All right. 184 184 00:09:51,320 --> 00:09:55,540 Finally, let's take a look at what happens with divisions 185 185 00:09:57,330 --> 00:10:00,763 because BigInt is indeed an integer. 186 186 00:10:01,860 --> 00:10:03,863 So what happens if we do this, 187 187 00:10:05,120 --> 00:10:08,820 10 divided by three n 188 188 00:10:08,820 --> 00:10:11,470 and we know that with normal numbers, 189 189 00:10:11,470 --> 00:10:14,490 this would not be an integer, right? 190 190 00:10:14,490 --> 00:10:19,490 So 10 divided by three is 3.33 until infinity. 191 191 00:10:19,850 --> 00:10:22,870 So here, but with BigInt, 192 192 00:10:22,870 --> 00:10:27,670 it will simply then return the closest BigInt. Right? 193 193 00:10:27,670 --> 00:10:29,713 Let's try it with 11 here, 194 194 00:10:31,330 --> 00:10:35,430 and so it simply basically cuts the decimal part off, 195 195 00:10:35,430 --> 00:10:39,950 of course with 12, it would then be four, right. 196 196 00:10:39,950 --> 00:10:41,370 But with anything else, 197 197 00:10:41,370 --> 00:10:45,450 it will then cut off the decimal part, okay. 198 198 00:10:45,450 --> 00:10:49,020 And basically, this is all that I have to tell you 199 199 00:10:49,020 --> 00:10:52,247 in an introduction video like this one about BigInt. 200 200 00:10:53,110 --> 00:10:55,040 So this new primitive type 201 201 00:10:55,040 --> 00:10:57,410 adds some new capabilities 202 202 00:10:57,410 --> 00:10:59,180 to the JavaScript language. 203 203 00:10:59,180 --> 00:11:02,837 When you really need to work with like huge numbers 204 204 00:11:02,837 --> 00:11:06,170 just like this one here, for example. 205 205 00:11:06,170 --> 00:11:10,920 Now in practice, you will probably not use this very much 206 206 00:11:10,920 --> 00:11:14,050 but it's still good to know that BigInt exists 207 207 00:11:14,050 --> 00:11:15,823 and also how it works. 17321