WEBVTT 1 00:00:01.755 --> 00:00:02.588 In this video, 2 00:00:02.588 --> 00:00:05.260 we need to go back to value types. 3 00:00:05.260 --> 00:00:08.180 So types are one of the fundamental aspects 4 00:00:08.180 --> 00:00:11.720 in programming, and converting between types 5 00:00:11.720 --> 00:00:15.010 is something that we do in every programming language. 6 00:00:15.010 --> 00:00:17.820 For example, converting a string to a number 7 00:00:17.820 --> 00:00:19.680 or a number into a Boolean 8 00:00:19.680 --> 00:00:22.110 is something that we do all the time. 9 00:00:22.110 --> 00:00:24.610 And so it's important that we learn about this 10 00:00:24.610 --> 00:00:28.170 before being able to move on further in the course. 11 00:00:28.170 --> 00:00:31.920 That's especially true for a language like JavaScript, 12 00:00:31.920 --> 00:00:34.790 which sometimes behaves in a weird way, 13 00:00:34.790 --> 00:00:36.713 as we will see in this video. 14 00:00:38.200 --> 00:00:41.040 Now, in JavaScript, there is type conversion 15 00:00:41.040 --> 00:00:42.870 and type coercion. 16 00:00:42.870 --> 00:00:46.050 So they sound very similar but are different. 17 00:00:46.050 --> 00:00:49.370 So type conversion is when we manually convert 18 00:00:49.370 --> 00:00:51.640 from one type to another. 19 00:00:51.640 --> 00:00:53.340 One the other hand, type coercion 20 00:00:53.340 --> 00:00:56.540 is when JavaScript automatically converts types 21 00:00:56.540 --> 00:00:58.610 behind the scenes for us. 22 00:00:58.610 --> 00:01:01.070 So that's necessary in some situation 23 00:01:01.070 --> 00:01:04.710 but it happens implicitly, completely hidden from us. 24 00:01:04.710 --> 00:01:05.880 Okay? 25 00:01:05.880 --> 00:01:08.060 So let's start with type conversion, 26 00:01:08.060 --> 00:01:11.040 which remember, is when we explicitly want 27 00:01:11.040 --> 00:01:13.800 to convert from one type to another. 28 00:01:13.800 --> 00:01:16.120 So let's say that we have an input field 29 00:01:16.120 --> 00:01:20.240 on a web page for the user to input their birth year. 30 00:01:20.240 --> 00:01:24.593 And these inputs from input fields usually come as strings. 31 00:01:26.300 --> 00:01:30.460 So let's say that the inputYear that we get 32 00:01:30.460 --> 00:01:32.700 from the user interface 33 00:01:32.700 --> 00:01:36.240 is a string with the value 1991. 34 00:01:36.240 --> 00:01:39.490 But now if we want to do some calculations with this, 35 00:01:39.490 --> 00:01:41.480 this won't really work. 36 00:01:41.480 --> 00:01:42.830 So let me show that to you. 37 00:01:43.780 --> 00:01:45.113 So console.log. 38 00:01:46.120 --> 00:01:47.860 Let's say inputYear, 39 00:01:47.860 --> 00:01:50.700 and now plus 18. 40 00:01:50.700 --> 00:01:52.460 And so like this we can calculate 41 00:01:52.460 --> 00:01:56.250 in what year the person will become of full age. 42 00:01:56.250 --> 00:01:59.200 Now, remember that when we have a string 43 00:01:59.200 --> 00:02:01.370 and add something to the string, 44 00:02:01.370 --> 00:02:04.430 it will basically concatenate the strings. 45 00:02:04.430 --> 00:02:08.650 So we can't expect that this actually adds 18 46 00:02:08.650 --> 00:02:11.253 to this number here because it's a string. 47 00:02:12.260 --> 00:02:15.030 So let me show you what I mean with that. 48 00:02:15.030 --> 00:02:17.810 And so indeed, we know get the string, 49 00:02:17.810 --> 00:02:20.960 which basically contains the 1991 string 50 00:02:20.960 --> 00:02:22.933 and then the 18 as well. 51 00:02:24.536 --> 00:02:27.410 So we need a way of fixing this, 52 00:02:27.410 --> 00:02:28.990 which means that we need a way 53 00:02:28.990 --> 00:02:32.650 of converting this string to a number. 54 00:02:32.650 --> 00:02:35.363 So let me actually log that here first. 55 00:02:36.400 --> 00:02:38.260 So console.log. 56 00:02:38.260 --> 00:02:41.580 And then the way we convert this string to a number 57 00:02:41.580 --> 00:02:45.570 is by using the built-in Number function. 58 00:02:45.570 --> 00:02:47.270 So we write number, 59 00:02:47.270 --> 00:02:51.060 then parenthesis, and then inputYear. 60 00:02:51.060 --> 00:02:53.690 And we will learn exactly what a function is 61 00:02:53.690 --> 00:02:57.640 and why it works this way in the next section. 62 00:02:57.640 --> 00:03:01.230 For now, just know that we can basically convert strings 63 00:03:01.230 --> 00:03:04.730 to numbers by using this function, 64 00:03:04.730 --> 00:03:08.770 which we execute using these parenthesis here. 65 00:03:08.770 --> 00:03:11.970 So we have this parenthesis inside this parenthesis now 66 00:03:11.970 --> 00:03:13.883 but don't get confused by that. 67 00:03:14.890 --> 00:03:17.505 So doing this operation here 68 00:03:17.505 --> 00:03:20.773 will then return the string as a number. 69 00:03:21.630 --> 00:03:22.980 So let me show that to you. 70 00:03:24.200 --> 00:03:26.990 And so indeed, now we get 1991 here 71 00:03:26.990 --> 00:03:29.930 in this pink color basically. 72 00:03:29.930 --> 00:03:32.850 And the colors might change throughout the time. 73 00:03:32.850 --> 00:03:34.890 By the time I record this video, 74 00:03:34.890 --> 00:03:39.320 numbers are pink and strings are just this white. 75 00:03:39.320 --> 00:03:40.920 Let me actually print them both. 76 00:03:43.700 --> 00:03:46.810 And so that should make it really visible 77 00:03:46.810 --> 00:03:49.310 that yeah, the first one is a number, 78 00:03:49.310 --> 00:03:51.500 the second one is a string. 79 00:03:51.500 --> 00:03:54.730 Okay, but now one thing that's really important 80 00:03:54.730 --> 00:03:57.460 to note here is that the original value 81 00:03:57.460 --> 00:03:59.570 is actually not converted. 82 00:03:59.570 --> 00:04:02.720 So the inputYear variable itself, 83 00:04:02.720 --> 00:04:06.080 so this one, is still a string, right? 84 00:04:06.080 --> 00:04:08.870 It still holds the variable 1991 85 00:04:08.870 --> 00:04:11.440 as a string and not as a number. 86 00:04:11.440 --> 00:04:14.040 That's why down here in this log, 87 00:04:14.040 --> 00:04:15.980 where we do this calculation, 88 00:04:15.980 --> 00:04:18.220 the result is still this string 89 00:04:18.220 --> 00:04:21.420 because again, the original inputYear variable 90 00:04:21.420 --> 00:04:22.930 is still a string. 91 00:04:22.930 --> 00:04:24.350 Using this number function 92 00:04:24.350 --> 00:04:27.563 will simply give to us a converted version. 93 00:04:28.580 --> 00:04:31.296 So if you want to perform this calculation, 94 00:04:31.296 --> 00:04:35.410 we need to use Number here as well. 95 00:04:35.410 --> 00:04:37.920 And so this will now convert the number 96 00:04:37.920 --> 00:04:41.460 and then to that number, the 18 will be added. 97 00:04:41.460 --> 00:04:46.460 And so now we should end up with something like 2009 I guess 98 00:04:47.500 --> 00:04:49.970 and indeed, that's right. 99 00:04:49.970 --> 00:04:52.700 But now what if we're trying to convert something 100 00:04:52.700 --> 00:04:55.676 to a number that is impossible to convert? 101 00:04:55.676 --> 00:04:59.750 Let's try that with a string 102 00:04:59.750 --> 00:05:01.980 that doesn't really contain a number. 103 00:05:01.980 --> 00:05:05.410 So let's try to console.log converting 104 00:05:05.410 --> 00:05:09.110 to a number the string Jonas. 105 00:05:09.110 --> 00:05:11.360 So JavaScript will look at the string, 106 00:05:11.360 --> 00:05:13.810 will try to convert it to a number 107 00:05:13.810 --> 00:05:15.470 but it won't really work. 108 00:05:15.470 --> 00:05:17.153 So what do we get instead? 109 00:05:18.000 --> 00:05:21.870 We get this NaN, which stands for not a number. 110 00:05:21.870 --> 00:05:25.040 So JavaScript gives us this not a number value 111 00:05:25.040 --> 00:05:28.330 whenever an operation that involves numbers fails 112 00:05:28.330 --> 00:05:30.670 to produce a new number. 113 00:05:30.670 --> 00:05:35.210 So basically, not a number actually means invalid number. 114 00:05:35.210 --> 00:05:37.100 It's not really not a number. 115 00:05:37.100 --> 00:05:39.143 And let me actually prove that to you. 116 00:05:41.130 --> 00:05:43.217 So we can check the typeof NaN. 117 00:05:46.085 --> 00:05:47.418 So not a number. 118 00:05:48.360 --> 00:05:49.393 And as you will see, 119 00:05:50.420 --> 00:05:53.960 the weird result of this is that the type 120 00:05:53.960 --> 00:05:56.220 of not a number is actually number 121 00:05:56.220 --> 00:06:01.220 and so again, not a number actually means an invalid number. 122 00:06:01.520 --> 00:06:03.060 It's still a number somehow 123 00:06:03.060 --> 00:06:04.623 but it's an invalid one. 124 00:06:06.211 --> 00:06:07.700 And so again, we get not a number 125 00:06:07.700 --> 00:06:11.170 whenever an operation involving numbers fails 126 00:06:11.170 --> 00:06:13.810 to give us a new number. 127 00:06:13.810 --> 00:06:17.200 Okay, so that is converting strings to numbers 128 00:06:17.200 --> 00:06:19.733 but, of course, we can also do the opposite. 129 00:06:22.130 --> 00:06:25.280 It's a little bit less important I would say 130 00:06:25.280 --> 00:06:27.283 but I still want to show it to you. 131 00:06:28.970 --> 00:06:30.910 So to do it the other way around, 132 00:06:30.910 --> 00:06:33.430 we use this String function. 133 00:06:33.430 --> 00:06:36.790 And that's quite straightforward, right? 134 00:06:36.790 --> 00:06:39.560 Just keep in mind that we need to really start it 135 00:06:39.560 --> 00:06:43.330 with a capital S, just like here the Number function needs 136 00:06:43.330 --> 00:06:45.540 to start with a capital N. 137 00:06:45.540 --> 00:06:47.103 Otherwise it's not gonna work. 138 00:06:48.760 --> 00:06:50.950 So we get 23. 139 00:06:50.950 --> 00:06:54.130 And remember that whenever the value here is white, 140 00:06:54.130 --> 00:06:56.330 then it means it is a string. 141 00:06:56.330 --> 00:06:58.095 So it looks kind of the same. 142 00:06:58.095 --> 00:07:03.095 Let's again log both just to make this point. 143 00:07:04.120 --> 00:07:05.920 So the pink one is the value 144 00:07:05.920 --> 00:07:08.240 that actually has the number type 145 00:07:08.240 --> 00:07:10.353 and this one has the string type. 146 00:07:11.550 --> 00:07:14.540 Okay, so again, this one is not as important 147 00:07:14.540 --> 00:07:16.740 but I still wanted to mention it. 148 00:07:16.740 --> 00:07:20.570 Now, JavaScript can only convert to three types. 149 00:07:20.570 --> 00:07:24.000 So we can convert to a number, to a string 150 00:07:24.000 --> 00:07:25.950 or to a Boolean. 151 00:07:25.950 --> 00:07:28.660 But we cannot, for example, convert something 152 00:07:28.660 --> 00:07:31.200 to undefined or to null. 153 00:07:31.200 --> 00:07:33.410 That doesn't make a lot of sense. 154 00:07:33.410 --> 00:07:35.730 Now, here we only converted to numbers 155 00:07:35.730 --> 00:07:38.550 and to strings but not to Booleans. 156 00:07:38.550 --> 00:07:41.920 And that's because Booleans behave in a special way. 157 00:07:41.920 --> 00:07:44.870 And for that reason, there is a separate lecture coming up 158 00:07:44.870 --> 00:07:47.973 on so-called truthy and falsy values. 159 00:07:48.920 --> 00:07:51.160 Great, so that is type conversion 160 00:07:51.160 --> 00:07:52.900 where we do manually convert 161 00:07:52.900 --> 00:07:55.040 from one type to another. 162 00:07:55.040 --> 00:07:56.430 However, in practice, 163 00:07:56.430 --> 00:07:58.770 we rarely have to do it manually 164 00:07:58.770 --> 00:08:02.240 because JavaScript actually does type coercion automatically 165 00:08:02.240 --> 00:08:04.470 for us in many situations. 166 00:08:04.470 --> 00:08:06.440 So let's talk about that now. 167 00:08:06.440 --> 00:08:08.750 And let's just separate this here 168 00:08:08.750 --> 00:08:09.983 with some comments. 169 00:08:11.320 --> 00:08:12.913 So type conversion. 170 00:08:14.060 --> 00:08:14.893 And then 171 00:08:18.390 --> 00:08:20.310 type coercion. 172 00:08:20.310 --> 00:08:22.820 So basically, type coercion happens 173 00:08:22.820 --> 00:08:26.310 whenever an operator is dealing with two values 174 00:08:26.310 --> 00:08:27.990 that have different types. 175 00:08:27.990 --> 00:08:31.440 So in that case, JavaScript will then, behind the scenes, 176 00:08:31.440 --> 00:08:35.030 convert one of the values to match the other value 177 00:08:35.030 --> 00:08:35.950 so that in the end, 178 00:08:35.950 --> 00:08:38.220 the operation can be executed. 179 00:08:38.220 --> 00:08:40.750 And actually, we already saw that happening 180 00:08:40.750 --> 00:08:41.963 if you think about this. 181 00:08:42.950 --> 00:08:47.200 So let me show that to you, 182 00:08:47.200 --> 00:08:48.973 starting with strings. 183 00:08:49.910 --> 00:08:51.650 Remember how we did this. 184 00:08:51.650 --> 00:08:53.930 I am and then a number. 185 00:08:53.930 --> 00:08:55.323 Let's say 23. 186 00:08:56.950 --> 00:09:00.683 And then another plus years old. 187 00:09:01.570 --> 00:09:04.130 So we already know that this is gonna produce a string 188 00:09:04.130 --> 00:09:07.050 that says I am 23 years old. 189 00:09:07.050 --> 00:09:09.240 But how does that actually work? 190 00:09:09.240 --> 00:09:11.420 Because 23 is a number. 191 00:09:11.420 --> 00:09:13.940 So we have different types here, right? 192 00:09:13.940 --> 00:09:17.263 We have a string, a number and another string. 193 00:09:18.340 --> 00:09:23.110 So let's check and indeed, that is what happens. 194 00:09:23.110 --> 00:09:26.190 And it works this way because of type coercion. 195 00:09:26.190 --> 00:09:28.380 So in JavaScript, the plus operator 196 00:09:28.380 --> 00:09:32.470 that we used here triggers a coercion to strings. 197 00:09:32.470 --> 00:09:35.100 And so whenever there is an operation between a string 198 00:09:35.100 --> 00:09:39.540 and a number, the number will be converted to a string. 199 00:09:39.540 --> 00:09:41.160 So thanks to type coercion, 200 00:09:41.160 --> 00:09:43.470 writing this would be exactly the same 201 00:09:43.470 --> 00:09:45.803 as writing this. 202 00:09:50.510 --> 00:09:51.343 Right? 203 00:09:51.343 --> 00:09:53.040 Because again, the plus operator 204 00:09:53.040 --> 00:09:55.780 will convert numbers to strings. 205 00:09:55.780 --> 00:09:58.610 And the same actually happens in template literals. 206 00:09:58.610 --> 00:10:00.790 It also takes all the number values 207 00:10:00.790 --> 00:10:03.500 and also converts them to strings. 208 00:10:03.500 --> 00:10:06.900 Now, if JavaScript did not have automatic type coercion, 209 00:10:06.900 --> 00:10:08.879 like many other languages don't, 210 00:10:08.879 --> 00:10:11.730 then we would have to manually do this 211 00:10:11.730 --> 00:10:13.890 like we just learned before. 212 00:10:13.890 --> 00:10:17.870 Then we would have to do String 23 213 00:10:17.870 --> 00:10:21.220 and then this would be the only way that this would work. 214 00:10:21.220 --> 00:10:22.560 But luckily for us, 215 00:10:22.560 --> 00:10:24.380 JavaScript has type coercion 216 00:10:24.380 --> 00:10:27.080 and so this will happen completely automatically 217 00:10:27.080 --> 00:10:28.680 behind the scenes. 218 00:10:28.680 --> 00:10:31.320 Now, actually not all the operators 219 00:10:31.320 --> 00:10:33.830 do type coercion to string. 220 00:10:33.830 --> 00:10:35.573 So let me show you something else. 221 00:10:37.110 --> 00:10:42.110 So if we do 23, the string minus 10 the string 222 00:10:44.010 --> 00:10:47.823 minus three, what do you think will happen now? 223 00:10:48.920 --> 00:10:50.830 So let's actually check 224 00:10:52.390 --> 00:10:53.863 and it gives us 10. 225 00:10:54.780 --> 00:10:56.210 So what happened here? 226 00:10:56.210 --> 00:10:58.407 It looks like this time JavaScript converted 227 00:10:58.407 --> 00:11:01.240 the strings to numbers. 228 00:11:01.240 --> 00:11:03.750 And indeed, that's why we get 10 229 00:11:03.750 --> 00:11:06.750 because 23 minus 10 is 13 230 00:11:06.750 --> 00:11:08.760 minus 3 is 10. 231 00:11:08.760 --> 00:11:11.640 And so what this means is that the minus operator 232 00:11:11.640 --> 00:11:14.280 actually triggers the opposite conversion. 233 00:11:14.280 --> 00:11:17.630 So in this case, strings are converted to numbers 234 00:11:17.630 --> 00:11:19.710 and not the other way around. 235 00:11:19.710 --> 00:11:23.120 So instead if we use the plus, 236 00:11:23.120 --> 00:11:24.820 what do you think is gonna happen? 237 00:11:26.500 --> 00:11:29.040 Then the three is converted to a string 238 00:11:29.040 --> 00:11:31.413 and then the three strings are concatenated. 239 00:11:32.570 --> 00:11:33.403 Okay? 240 00:11:33.403 --> 00:11:35.380 So this is a very important distinction 241 00:11:35.380 --> 00:11:37.020 to keep in mind 242 00:11:37.020 --> 00:11:40.470 because this actually confuses many JavaScript beginners 243 00:11:40.470 --> 00:11:42.070 when they don't know about this. 244 00:11:43.930 --> 00:11:45.880 So let's try another one here 245 00:11:45.880 --> 00:11:49.190 and I'm again using 23 the string 246 00:11:49.190 --> 00:11:51.800 times two, the string. 247 00:11:51.800 --> 00:11:53.630 And again, you will see that these values 248 00:11:53.630 --> 00:11:57.303 are gonna be converted to numbers before. 249 00:11:58.190 --> 00:12:00.780 And indeed, that's why we get 46 250 00:12:00.780 --> 00:12:04.030 because both of them are now converted to numbers 251 00:12:04.030 --> 00:12:05.360 because that's the only way 252 00:12:05.360 --> 00:12:08.920 that the multiplier operator can work. 253 00:12:08.920 --> 00:12:11.763 And the same, of course, is true for dividing. 254 00:12:14.260 --> 00:12:18.820 Okay, so I hope that the distinction between type conversion 255 00:12:18.820 --> 00:12:22.270 and type coercion is now pretty clear. 256 00:12:22.270 --> 00:12:25.350 And now just to make sure that you actually got it, 257 00:12:25.350 --> 00:12:28.690 let's play a game called guess the output. 258 00:12:28.690 --> 00:12:30.883 So that's a game I just made up. 259 00:12:31.830 --> 00:12:34.420 So I want you to guess what happens here. 260 00:12:34.420 --> 00:12:39.420 So I'll write one plus one like this. 261 00:12:40.590 --> 00:12:45.590 And then we say n equals n minus one again. 262 00:12:52.800 --> 00:12:55.800 So what do you think n will look like 263 00:12:55.800 --> 00:12:57.960 when we log it to the console? 264 00:12:57.960 --> 00:13:00.710 So essentially, we start with one the string, 265 00:13:00.710 --> 00:13:03.403 then we add one and then we subtract one. 266 00:13:05.060 --> 00:13:06.950 So take a moment to think 267 00:13:06.950 --> 00:13:08.310 what this should look like 268 00:13:08.310 --> 00:13:11.380 and then let's take a look at the solution. 269 00:13:11.380 --> 00:13:13.773 And it is 10. 270 00:13:14.690 --> 00:13:16.940 So that's a bit counterintuitive 271 00:13:16.940 --> 00:13:18.430 but according to the rules 272 00:13:18.430 --> 00:13:19.840 that we just learned before, 273 00:13:19.840 --> 00:13:21.460 it actually makes sense. 274 00:13:21.460 --> 00:13:23.170 So here in the first line, 275 00:13:23.170 --> 00:13:26.140 one plus one will actually turn out 276 00:13:26.140 --> 00:13:27.930 to be 11, the string 277 00:13:27.930 --> 00:13:29.800 because we have one string here 278 00:13:29.800 --> 00:13:31.550 and then the plus operator 279 00:13:31.550 --> 00:13:33.160 will automatically convert the number 280 00:13:33.160 --> 00:13:34.120 to a string. 281 00:13:34.120 --> 00:13:38.850 And so the result of this one is the string 11. 282 00:13:38.850 --> 00:13:41.470 But then here we have the minus operator. 283 00:13:41.470 --> 00:13:43.110 And in the minus operator, 284 00:13:43.110 --> 00:13:45.970 whenever we have a string or more strings, 285 00:13:45.970 --> 00:13:48.220 it will then convert it to a number. 286 00:13:48.220 --> 00:13:51.140 And so here the string 11 will be converted 287 00:13:51.140 --> 00:13:54.880 to 11 the number and then 11 minus one 288 00:13:54.880 --> 00:13:56.143 is, of course, 10. 289 00:13:57.790 --> 00:14:00.010 Okay, let's do one or two more 290 00:14:00.010 --> 00:14:02.130 and let's do it in the console here. 291 00:14:02.130 --> 00:14:04.230 And we can actually clear the console 292 00:14:04.230 --> 00:14:06.650 of all this clutter here 293 00:14:06.650 --> 00:14:08.523 by clicking on clear console. 294 00:14:09.828 --> 00:14:14.828 So let's do two plus three plus four plus five, the string. 295 00:14:16.570 --> 00:14:18.570 And now you actually can't really guess 296 00:14:18.570 --> 00:14:21.404 because we can already see the solution there. 297 00:14:21.404 --> 00:14:24.640 So let's try to understand what happened here. 298 00:14:24.640 --> 00:14:27.950 So we start here with two plus three, 299 00:14:27.950 --> 00:14:29.380 which makes five. 300 00:14:29.380 --> 00:14:32.650 Then five plus four makes nine 301 00:14:32.650 --> 00:14:36.460 and then we end up with nine plus five, the string. 302 00:14:36.460 --> 00:14:38.270 And then as you already know, 303 00:14:38.270 --> 00:14:39.500 since we have a string, 304 00:14:39.500 --> 00:14:42.650 the plus operator will convert the other operand, 305 00:14:42.650 --> 00:14:44.800 which is nine also to a string 306 00:14:44.800 --> 00:14:47.973 and then we end up with 95 as a string. 307 00:14:48.910 --> 00:14:50.440 Okay, and another one. 308 00:14:50.440 --> 00:14:53.350 10 minus 4 309 00:14:54.950 --> 00:14:57.530 minus three, 310 00:14:57.530 --> 00:14:59.790 and keep in mind that these are strings, 311 00:14:59.790 --> 00:15:03.510 and then minus the real number two. 312 00:15:03.510 --> 00:15:05.343 But then plus five the string. 313 00:15:06.310 --> 00:15:08.330 So again, this looks very weird 314 00:15:08.330 --> 00:15:11.270 but the logic is kind of the same as before. 315 00:15:11.270 --> 00:15:15.040 So we have two values that are subtracted 316 00:15:15.040 --> 00:15:18.400 and so JavaScript will convert them both to numbers 317 00:15:18.400 --> 00:15:21.290 and so the result of this is six. 318 00:15:21.290 --> 00:15:25.140 Then six minus three is three. 319 00:15:25.140 --> 00:15:27.560 Then three minus two is one. 320 00:15:27.560 --> 00:15:30.640 And then we end up with the same situation as before. 321 00:15:30.640 --> 00:15:33.750 So this one will be converted to a string 322 00:15:33.750 --> 00:15:35.533 and then we end up with the string 15. 323 00:15:37.990 --> 00:15:39.000 Okay. 324 00:15:39.000 --> 00:15:42.680 And with that, I think this should be pretty clear now. 325 00:15:42.680 --> 00:15:45.160 And you might be wondering why we're talking so much 326 00:15:45.160 --> 00:15:47.400 about this but it's really important 327 00:15:47.400 --> 00:15:49.900 that you know about this right from the start 328 00:15:49.900 --> 00:15:51.640 so that you can write your code 329 00:15:51.640 --> 00:15:53.690 with all of this in mind. 330 00:15:53.690 --> 00:15:56.630 Now, many people actually don't like type coercion 331 00:15:56.630 --> 00:15:58.630 and think that it's a bad practice 332 00:15:58.630 --> 00:16:01.120 to rely on type coercion. 333 00:16:01.120 --> 00:16:02.180 One reason for that 334 00:16:02.180 --> 00:16:04.820 is that type coercion can, in fact, 335 00:16:04.820 --> 00:16:08.770 introduce many unexpected bugs into our program. 336 00:16:08.770 --> 00:16:12.100 However, this only happens when we don't really know 337 00:16:12.100 --> 00:16:13.260 what we're doing. 338 00:16:13.260 --> 00:16:15.130 So when we don't know about the stuff 339 00:16:15.130 --> 00:16:16.400 that I just showed you 340 00:16:16.400 --> 00:16:18.510 because if you know, then it's way easier 341 00:16:18.510 --> 00:16:20.590 to avoid these errors. 342 00:16:20.590 --> 00:16:24.800 So in my opinion, coercion is actually a great mechanism 343 00:16:24.800 --> 00:16:27.670 that is gonna allow us to write a lot less code 344 00:16:27.670 --> 00:16:30.900 and also to write more readable code. 345 00:16:30.900 --> 00:16:32.960 So really make sure to take some time 346 00:16:32.960 --> 00:16:35.480 to understand how type coercion works 347 00:16:35.480 --> 00:16:38.083 and then just embrace it in your code.