1 00:00:01,310 --> 00:00:02,930 Over the next few lectures, 2 00:00:02,930 --> 00:00:06,280 we will learn how to work with strings 3 00:00:06,280 --> 00:00:08,130 and so we're gonna be taking a look 4 00:00:08,130 --> 00:00:11,230 at a couple of useful string methods. 5 00:00:11,230 --> 00:00:14,160 Now I could have divided this part about strings 6 00:00:14,160 --> 00:00:15,610 into many more lectures 7 00:00:15,610 --> 00:00:18,780 and go really deep into some topics 8 00:00:18,780 --> 00:00:22,170 but I think it's best to just quickly introduce you 9 00:00:22,170 --> 00:00:23,950 to all the topics here 10 00:00:23,950 --> 00:00:26,800 and then keep using them in future projects 11 00:00:26,800 --> 00:00:30,700 because we work with strings all the time in JavaScript 12 00:00:30,700 --> 00:00:33,330 and so you will see these methods being used 13 00:00:33,330 --> 00:00:36,400 all the time throughout the rest of the course. 14 00:00:36,400 --> 00:00:39,080 Anyway, this is gonna be really fun 15 00:00:39,080 --> 00:00:40,653 so let's get started. 16 00:00:42,210 --> 00:00:43,950 And in this part of the section, 17 00:00:43,950 --> 00:00:46,850 we're gonna leave the restaurant theme behind 18 00:00:46,850 --> 00:00:51,590 and work on stuff related to airplanes and airlines. 19 00:00:51,590 --> 00:00:54,360 So that's something that I really like. 20 00:00:54,360 --> 00:00:59,360 So let's now start by creating an airline variable here 21 00:01:00,530 --> 00:01:03,283 and I'm using TAP Air Portugal. 22 00:01:06,920 --> 00:01:10,740 All right, and if you want, you can use some other one 23 00:01:10,740 --> 00:01:12,163 from your country maybe, 24 00:01:13,100 --> 00:01:16,340 but then you might have to adapt the examples. 25 00:01:16,340 --> 00:01:17,540 So as a plane, 26 00:01:17,540 --> 00:01:20,843 I'm using a string A320. 27 00:01:21,710 --> 00:01:22,543 Okay. 28 00:01:22,543 --> 00:01:25,300 And now let's do some stuff with this. 29 00:01:25,300 --> 00:01:26,600 So just like in arrays, 30 00:01:26,600 --> 00:01:30,923 we can get the character of a string at a certain position. 31 00:01:31,970 --> 00:01:36,290 So for example, plane at position zero 32 00:01:36,290 --> 00:01:38,750 should be A, right? 33 00:01:38,750 --> 00:01:41,550 So let's load this here. 34 00:01:41,550 --> 00:01:42,777 And indeed we got A 35 00:01:43,775 --> 00:01:46,363 and the same of course for all the other letters, 36 00:01:47,450 --> 00:01:49,990 one, two for example. 37 00:01:49,990 --> 00:01:53,730 And so indeed you now get three and two here 38 00:01:53,730 --> 00:01:56,370 but both of them are still strings. 39 00:01:56,370 --> 00:01:58,570 So if we wanted them to be numbers, 40 00:01:58,570 --> 00:02:03,036 we would have to convert them and we can do the same 41 00:02:03,036 --> 00:02:05,333 directly on a string. 42 00:02:06,440 --> 00:02:11,150 So we can just write a string and let's write B727 now, 43 00:02:11,150 --> 00:02:15,263 which is a Boeing and so this works the same. 44 00:02:16,630 --> 00:02:18,910 Okay so now we got to the B, 45 00:02:18,910 --> 00:02:22,133 we can also read the length property of strings, 46 00:02:23,369 --> 00:02:25,590 just like we can in arrays. 47 00:02:25,590 --> 00:02:29,470 So let's say airline.length. 48 00:02:29,470 --> 00:02:32,513 And again we can also do that directly on the string. 49 00:02:36,590 --> 00:02:37,840 Okay. 50 00:02:37,840 --> 00:02:38,673 There you go. 51 00:02:39,520 --> 00:02:42,330 Next up let's talk about methods. 52 00:02:42,330 --> 00:02:45,560 So again comparing strings to arrays here, 53 00:02:45,560 --> 00:02:48,180 strings also have methods 54 00:02:48,180 --> 00:02:52,170 and some of them are quite similar to the array methods. 55 00:02:52,170 --> 00:02:54,713 So one of them is the index off. 56 00:02:56,250 --> 00:02:58,870 So I believe we talked about this one 57 00:02:58,870 --> 00:03:00,795 when we talked about a array. 58 00:03:00,795 --> 00:03:02,760 And so this one works the same way, 59 00:03:02,760 --> 00:03:05,754 so we can get the position in which a certain letter 60 00:03:05,754 --> 00:03:07,770 is in the string. 61 00:03:07,770 --> 00:03:09,343 So let's use r here. 62 00:03:11,190 --> 00:03:14,490 And so here we now get to position number six. 63 00:03:14,490 --> 00:03:19,490 And so let's see zero, one, two, three, four, five and six. 64 00:03:21,740 --> 00:03:24,713 Okay and that's where the six here comes from. 65 00:03:25,830 --> 00:03:30,130 So you'll see that strings are also zero-based right? 66 00:03:30,130 --> 00:03:32,973 And we could observe that already up here. 67 00:03:33,890 --> 00:03:37,290 Now this here will only give us the first occurrence 68 00:03:37,290 --> 00:03:40,090 but sometimes we might need the last one. 69 00:03:40,090 --> 00:03:42,323 And so then we can use lastIndexOf, 70 00:03:45,860 --> 00:03:49,940 lastIndexOf and so that is 10. 71 00:03:49,940 --> 00:03:53,040 So this one was six then seven, 72 00:03:53,040 --> 00:03:56,780 because the space of course also counts as a character, 73 00:03:56,780 --> 00:03:59,523 then eight, nine, and this is position 10. 74 00:04:00,840 --> 00:04:05,683 Alright and we can also search for entire words. 75 00:04:10,260 --> 00:04:14,313 For example, for the occurrence of Portugal, 76 00:04:15,280 --> 00:04:17,530 and so that is at position eight, 77 00:04:17,530 --> 00:04:20,040 and this one is actually case sensitive. 78 00:04:20,040 --> 00:04:22,460 So if I search with lowercase, 79 00:04:22,460 --> 00:04:24,080 then we get minus one, 80 00:04:24,080 --> 00:04:26,350 because this can now not be found 81 00:04:26,350 --> 00:04:29,010 in this airline's string. 82 00:04:29,010 --> 00:04:34,010 All right now, what can we actually do with these indexes? 83 00:04:34,180 --> 00:04:36,050 Why are they useful? 84 00:04:36,050 --> 00:04:39,610 Well, one good use case is to extract part 85 00:04:39,610 --> 00:04:42,800 of a string using the slice method 86 00:04:42,800 --> 00:04:46,390 and a slice method needs indexes as arguments. 87 00:04:46,390 --> 00:04:49,280 And so therefore sometimes it can be very useful 88 00:04:49,280 --> 00:04:52,900 to first figure out the index of part of a string 89 00:04:52,900 --> 00:04:54,940 to then extract that. 90 00:04:54,940 --> 00:04:59,623 So let's see how the slice method works. 91 00:05:02,470 --> 00:05:06,140 So airline and then dot slice, 92 00:05:06,140 --> 00:05:09,583 and let's write four and see the result here. 93 00:05:10,810 --> 00:05:15,090 All right so the result is Air Portugal. 94 00:05:15,090 --> 00:05:17,870 And the reason for that is that this here 95 00:05:17,870 --> 00:05:19,660 is the begin parameter. 96 00:05:19,660 --> 00:05:21,930 So basically it's the position at which 97 00:05:21,930 --> 00:05:23,763 the extraction will start. 98 00:05:24,960 --> 00:05:27,970 And remember that this is zero based. 99 00:05:27,970 --> 00:05:31,870 So zero, one, two, three, and four. 100 00:05:31,870 --> 00:05:34,580 So four happens to be this A. 101 00:05:34,580 --> 00:05:38,663 And so this is where the slice method starts to extract. 102 00:05:38,663 --> 00:05:41,502 And this result that we get here, 103 00:05:41,502 --> 00:05:45,250 so just this here is called a substring 104 00:05:45,250 --> 00:05:48,981 because it's just a part of the original string. 105 00:05:48,981 --> 00:05:52,870 Now this does not change the underlying string okay? 106 00:05:52,870 --> 00:05:54,600 Just keep that in mind. 107 00:05:54,600 --> 00:05:58,410 That's because it's actually impossible to mutate strings. 108 00:05:58,410 --> 00:06:00,000 They are primitives, right? 109 00:06:00,000 --> 00:06:02,880 So if we wanted to use this string 110 00:06:02,880 --> 00:06:06,475 now we would have to store it first into some variable 111 00:06:06,475 --> 00:06:08,800 or some data structure. 112 00:06:08,800 --> 00:06:13,170 Okay, so this method here and all the other ones 113 00:06:13,170 --> 00:06:17,230 that we're gonna talk about always return a new string. 114 00:06:17,230 --> 00:06:20,680 Okay and so that's why we can then lock that result 115 00:06:20,680 --> 00:06:22,283 to the console like this. 116 00:06:23,240 --> 00:06:27,060 Now, besides the begin parameter that we already specified, 117 00:06:27,060 --> 00:06:30,630 we can also specify an end parameter. 118 00:06:30,630 --> 00:06:32,733 So let's try seven and see the result. 119 00:06:33,850 --> 00:06:36,390 And so now we only got air. 120 00:06:36,390 --> 00:06:41,390 Okay so this one is four, then five, six 121 00:06:41,660 --> 00:06:43,560 and seven is the space here. 122 00:06:43,560 --> 00:06:46,460 And so what this means is that the end value 123 00:06:46,460 --> 00:06:49,650 is actually not included in the string. 124 00:06:49,650 --> 00:06:52,840 All right so basically it stops extracting 125 00:06:52,840 --> 00:06:55,610 before reaching index number seven. 126 00:06:55,610 --> 00:06:58,060 And that's really important to keep in mind. 127 00:06:58,060 --> 00:06:59,700 And just as a side note, 128 00:06:59,700 --> 00:07:02,019 the length of the extracted string 129 00:07:02,019 --> 00:07:05,550 is always going to be end minus beginning. 130 00:07:05,550 --> 00:07:07,910 So seven minus four is three. 131 00:07:07,910 --> 00:07:10,710 And so that's the length here of air. 132 00:07:10,710 --> 00:07:14,150 All right, okay. 133 00:07:14,150 --> 00:07:16,070 Now up until this point, 134 00:07:16,070 --> 00:07:19,350 we have always just hard-coded these values, 135 00:07:19,350 --> 00:07:22,333 but ofcourse many times we don't even know the string 136 00:07:22,333 --> 00:07:24,508 that we receive yet okay? 137 00:07:24,508 --> 00:07:28,472 And so let's now try to extract just the first word 138 00:07:28,472 --> 00:07:30,147 of this string here, 139 00:07:30,147 --> 00:07:33,490 but without knowing any of the indexes. 140 00:07:33,490 --> 00:07:36,450 And so that's where this IndexOf, 141 00:07:36,450 --> 00:07:40,100 and lastIndexOf here become really important. 142 00:07:40,100 --> 00:07:43,310 So basically that we do not have to hard code 143 00:07:43,310 --> 00:07:44,823 these values here. 144 00:07:46,100 --> 00:07:50,820 All right so let's try to extract that first word 145 00:07:50,820 --> 00:07:51,803 as I was saying. 146 00:07:54,650 --> 00:07:56,910 Airline.slice 147 00:07:56,910 --> 00:07:59,790 and now we need to figure out the index. 148 00:07:59,790 --> 00:08:04,790 And now if we want the first word we need to start at zero, 149 00:08:04,840 --> 00:08:07,850 but what about the end parameter? 150 00:08:07,850 --> 00:08:12,620 Well we want to extract until this space here basically. 151 00:08:12,620 --> 00:08:14,823 So let's find the index of that. 152 00:08:16,060 --> 00:08:17,690 So airline.indexOf, 153 00:08:19,680 --> 00:08:22,751 and remember that this will be the first occurrence 154 00:08:22,751 --> 00:08:26,793 and so indeed we get top. 155 00:08:28,640 --> 00:08:32,040 All right and now let's do the opposite extracting 156 00:08:32,040 --> 00:08:36,890 the last word, so slice. 157 00:08:36,890 --> 00:08:38,070 And so for the last word, 158 00:08:38,070 --> 00:08:41,323 we want to start at the last space here. 159 00:08:42,410 --> 00:08:45,173 Okay that's why we have lastIndexOf. 160 00:08:46,760 --> 00:08:48,740 So airline.lastIndexOf 161 00:08:50,800 --> 00:08:53,200 and again searching for the space. 162 00:08:53,200 --> 00:08:55,560 And now we don't need the end parameter 163 00:08:55,560 --> 00:08:57,554 because then if we don't specify it, 164 00:08:57,554 --> 00:09:00,643 it will simply extract everything until the end. 165 00:09:01,720 --> 00:09:02,910 Okay. 166 00:09:02,910 --> 00:09:06,600 But actually now the space is also included here. 167 00:09:06,600 --> 00:09:09,893 And so we just need to add plus one, 168 00:09:11,270 --> 00:09:12,573 and now we're good. 169 00:09:14,550 --> 00:09:18,550 So that's the fundamentals of the slice method, 170 00:09:18,550 --> 00:09:21,183 but we can do even more with it. 171 00:09:22,380 --> 00:09:25,640 So let's go again here. 172 00:09:25,640 --> 00:09:29,740 And we can even define a negative begin argument. 173 00:09:29,740 --> 00:09:31,240 Like this for example, 174 00:09:31,240 --> 00:09:34,740 and then it will start counting from the end. 175 00:09:34,740 --> 00:09:37,513 Or actually start extracting from the end. 176 00:09:38,710 --> 00:09:42,500 So these are the last two letters from Portugal. 177 00:09:42,500 --> 00:09:45,830 And finally let's duplicate this one again. 178 00:09:45,830 --> 00:09:50,053 And again I'm using this shortcut here for duplicate. 179 00:09:51,140 --> 00:09:52,800 Okay. 180 00:09:52,800 --> 00:09:57,220 So we can also specify a negative end parameter. 181 00:09:57,220 --> 00:09:59,490 So the beginning is back to positive, 182 00:09:59,490 --> 00:10:02,150 and now the end is minus one. 183 00:10:02,150 --> 00:10:03,900 So let's see. 184 00:10:03,900 --> 00:10:06,793 And so basically we started at position one. 185 00:10:07,640 --> 00:10:09,840 So that's why the T is cut off. 186 00:10:09,840 --> 00:10:12,090 And then the negative end parameter, 187 00:10:12,090 --> 00:10:14,523 basically cuts off the last character. 188 00:10:15,720 --> 00:10:17,050 All right. 189 00:10:17,050 --> 00:10:18,540 And so we will need all of these 190 00:10:18,540 --> 00:10:20,230 different combinations here, 191 00:10:20,230 --> 00:10:22,160 in different situations. 192 00:10:22,160 --> 00:10:24,580 So it's good that you know how to use them, 193 00:10:24,580 --> 00:10:27,093 because you will need them at some point. 194 00:10:28,000 --> 00:10:28,833 Okay. 195 00:10:28,833 --> 00:10:30,730 And now let's practice a little bit, 196 00:10:30,730 --> 00:10:32,250 what we just learned 197 00:10:32,250 --> 00:10:36,120 and write a function that receives an airplane seat 198 00:10:36,120 --> 00:10:37,710 and locks to the console, 199 00:10:37,710 --> 00:10:40,870 whether it is a middle seat or not. 200 00:10:40,870 --> 00:10:43,760 I hope that sounds like fun. 201 00:10:43,760 --> 00:10:44,803 So let's write. 202 00:10:46,370 --> 00:10:47,690 Check, 203 00:10:47,690 --> 00:10:48,830 middle, 204 00:10:48,830 --> 00:10:49,663 seat. 205 00:10:50,640 --> 00:10:54,113 And it is a function which takes in a seat. 206 00:10:55,290 --> 00:10:57,860 And just to illustrate it, 207 00:10:57,860 --> 00:11:01,200 let me start by calling this function. 208 00:11:01,200 --> 00:11:02,763 To check middle seat. 209 00:11:03,830 --> 00:11:04,830 And so typically, 210 00:11:04,830 --> 00:11:07,380 an airplane seat looks like this. 211 00:11:07,380 --> 00:11:10,400 So we have the row as a number here 212 00:11:10,400 --> 00:11:12,280 and then the seat itself, 213 00:11:12,280 --> 00:11:14,897 so that's like the column so to say, 214 00:11:14,897 --> 00:11:18,360 it's then a letter for example a B. 215 00:11:18,360 --> 00:11:19,580 So it starts from the left 216 00:11:19,580 --> 00:11:22,140 and goes all the way to the right side. 217 00:11:22,140 --> 00:11:26,550 And in small planes, like the A320, or the Boeing 737, 218 00:11:26,550 --> 00:11:29,160 we only have six seats in one row. 219 00:11:29,160 --> 00:11:33,860 And that means that B and E are the middle seats. 220 00:11:33,860 --> 00:11:35,680 Let me just write that here. 221 00:11:35,680 --> 00:11:37,023 B and E, 222 00:11:38,470 --> 00:11:40,550 are middle seats. 223 00:11:40,550 --> 00:11:42,280 So just in case you're not familiar 224 00:11:42,280 --> 00:11:45,100 with how these small planes works. 225 00:11:45,100 --> 00:11:45,933 Right. 226 00:11:45,933 --> 00:11:48,570 And that's also not the point here of course. 227 00:11:48,570 --> 00:11:50,750 So basically all we want to do is to check 228 00:11:50,750 --> 00:11:52,880 if the string that we receive, 229 00:11:52,880 --> 00:11:54,720 contains a, B or an E. 230 00:11:54,720 --> 00:11:56,513 And if so, then it's a middle seat. 231 00:11:57,760 --> 00:12:01,090 And let's call this with a couple of different strings. 232 00:12:01,090 --> 00:12:02,130 So 23C 233 00:12:07,303 --> 00:12:08,136 and 3E. 234 00:12:10,120 --> 00:12:14,250 All right, so what we need to do here is basically 235 00:12:14,250 --> 00:12:17,400 take the last character of the string 236 00:12:17,400 --> 00:12:21,283 and test whether it is a B or an E right? 237 00:12:22,510 --> 00:12:25,530 So let's get that letter from the seat. 238 00:12:25,530 --> 00:12:28,570 Now we'll just call it S for seat again, 239 00:12:28,570 --> 00:12:31,280 but I cannot repeat the same name here. 240 00:12:31,280 --> 00:12:33,523 So how do I do that now? 241 00:12:34,980 --> 00:12:37,300 Well to extract part of a string, 242 00:12:37,300 --> 00:12:40,796 we already know we use the slice method 243 00:12:40,796 --> 00:12:44,962 and how do we take the last character of a certain string? 244 00:12:44,962 --> 00:12:49,280 Well, we use minus one as the begin character. 245 00:12:49,280 --> 00:12:51,207 And then as we saw up here, 246 00:12:51,207 --> 00:12:55,473 it will start counting basically one from the right side. 247 00:12:56,400 --> 00:12:57,963 And now it's very easy. 248 00:12:59,540 --> 00:13:03,610 If S equals B 249 00:13:04,708 --> 00:13:09,708 or if S equals E, 250 00:13:12,070 --> 00:13:13,763 then let's log to the console, 251 00:13:15,270 --> 00:13:18,065 you got the middle seat, 252 00:13:18,065 --> 00:13:20,960 which is the one that no one wants. 253 00:13:20,960 --> 00:13:23,923 Well, let's add an emoji here. 254 00:13:26,270 --> 00:13:27,200 Let's say this one 255 00:13:28,740 --> 00:13:29,590 or else 256 00:13:33,880 --> 00:13:36,633 you got lucky, 257 00:13:39,220 --> 00:13:40,370 just any emoji here, 258 00:13:40,370 --> 00:13:42,030 just to make it different 259 00:13:43,030 --> 00:13:45,030 and I think we are good now. 260 00:13:45,030 --> 00:13:45,913 Let's test it. 261 00:13:47,010 --> 00:13:50,950 And so indeed this here contains the B at the end. 262 00:13:50,950 --> 00:13:52,840 And so therefore it's a middle seat, 263 00:13:52,840 --> 00:13:55,020 the same for this one 264 00:13:55,020 --> 00:13:58,653 and this person with this seat got lucky. 265 00:13:59,490 --> 00:14:03,900 All right and that's how we extract parts of strings. 266 00:14:03,900 --> 00:14:06,800 And that's something really important to do. 267 00:14:06,800 --> 00:14:08,160 So maybe if you'd like, 268 00:14:08,160 --> 00:14:10,160 you can play around with this some more, 269 00:14:10,160 --> 00:14:12,740 maybe come up with your own example. 270 00:14:12,740 --> 00:14:14,490 Now before we move on here, 271 00:14:14,490 --> 00:14:16,950 let's just stop for a second 272 00:14:16,950 --> 00:14:20,730 and understand why all of this actually works. 273 00:14:20,730 --> 00:14:23,900 So we know that strings are just primitives. 274 00:14:23,900 --> 00:14:26,500 So why do they have methods? 275 00:14:26,500 --> 00:14:28,710 Shouldn't methods only be available 276 00:14:28,710 --> 00:14:31,214 on objects such as a race? 277 00:14:31,214 --> 00:14:33,840 Well that is actually true. 278 00:14:33,840 --> 00:14:37,010 However, JavaScript is really smart. 279 00:14:37,010 --> 00:14:39,190 And so here is how this works. 280 00:14:39,190 --> 00:14:41,960 Whenever we call a method on a string, 281 00:14:41,960 --> 00:14:45,230 JavaScript will automatically behind the scenes 282 00:14:45,230 --> 00:14:49,080 convert that string primitive to a string object 283 00:14:49,080 --> 00:14:50,940 with the same content. 284 00:14:50,940 --> 00:14:55,220 And then it's on that object where the methods are called. 285 00:14:55,220 --> 00:14:58,850 All right and this process is called boxing 286 00:14:58,850 --> 00:15:01,370 because it basically takes our string 287 00:15:01,370 --> 00:15:03,460 and puts it into a box 288 00:15:03,460 --> 00:15:05,510 which is the object. 289 00:15:05,510 --> 00:15:08,253 So basically what happens is this. 290 00:15:11,820 --> 00:15:14,163 So what JavaScript does, 291 00:15:15,190 --> 00:15:17,363 is to call this string function here. 292 00:15:20,980 --> 00:15:21,813 Okay. 293 00:15:21,813 --> 00:15:24,960 And so now you'll see, that this string here, 294 00:15:24,960 --> 00:15:27,860 looks a little bit more like an object. 295 00:15:27,860 --> 00:15:29,920 And we could take a look at this here. 296 00:15:29,920 --> 00:15:32,883 And so you see here, all of these methods, 297 00:15:33,840 --> 00:15:36,690 like slice that we just use. 298 00:15:36,690 --> 00:15:38,700 But this is beyond the scope of this lecture. 299 00:15:38,700 --> 00:15:42,210 We will learn what this is a little bit later. 300 00:15:42,210 --> 00:15:46,713 But what matters is that this indeed is now an object. 301 00:15:48,380 --> 00:15:50,580 So you see it is an object. 302 00:15:50,580 --> 00:15:52,400 And so this conversion here 303 00:15:52,400 --> 00:15:54,930 is what JavaScript does behind the scenes 304 00:15:54,930 --> 00:15:58,450 whenever we call a method on a string. 305 00:15:58,450 --> 00:16:01,020 And then when the operation is done 306 00:16:01,020 --> 00:16:05,200 the object is converted back to a regular string primitive. 307 00:16:05,200 --> 00:16:06,400 Okay. 308 00:16:06,400 --> 00:16:09,740 And in fact all string methods return primitives. 309 00:16:09,740 --> 00:16:12,733 Even if called on a string object. 310 00:16:13,640 --> 00:16:16,773 So let me demonstrate us here as well. 311 00:16:19,930 --> 00:16:21,163 Just really quick. 312 00:16:25,260 --> 00:16:27,113 And actually we want your type off. 313 00:16:29,760 --> 00:16:31,750 And so the result of all of this, 314 00:16:31,750 --> 00:16:33,683 is then back to being a string. 315 00:16:35,640 --> 00:16:37,623 Okay, but don't get confused by this. 316 00:16:37,623 --> 00:16:40,210 This is just a theory explanation 317 00:16:40,210 --> 00:16:44,030 behind why all of this works in case you're curious. 318 00:16:44,030 --> 00:16:45,870 And I hope you are. 319 00:16:45,870 --> 00:16:46,703 Great. 320 00:16:46,703 --> 00:16:48,520 But now let's move on to the next video, 321 00:16:48,520 --> 00:16:51,163 where we will continue working with strings.