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.