1 00:00:01,350 --> 00:00:04,290 Let's get started with string comparison. 2 00:00:04,440 --> 00:00:06,480 Well, so far we are down with that. 3 00:00:06,480 --> 00:00:13,170 Strength matters because right now I have opened the gateway for you and you can learn any methods that 4 00:00:13,170 --> 00:00:15,300 you want to use in your future project. 5 00:00:15,300 --> 00:00:23,160 And always they are always online around and then find the particular strain metallurgy you want to 6 00:00:23,160 --> 00:00:25,140 use in your future project. 7 00:00:25,230 --> 00:00:27,270 Well, so let's comment out this one. 8 00:00:27,300 --> 00:00:31,440 Let's start with a new concept which is called string comparison. 9 00:00:31,440 --> 00:00:35,760 Meaning how can you compare string together in this video? 10 00:00:35,790 --> 00:00:42,210 I'm going to expose to you sometimes how JavaScript behave the way we don't explain it, right? 11 00:00:42,210 --> 00:00:50,850 But here the case you have no option unless you would be more about JavaScript before we can understand 12 00:00:50,850 --> 00:00:53,550 sometimes the weird things about JavaScript. 13 00:00:53,760 --> 00:00:57,990 So in this video, let's see how we can compare strings together. 14 00:00:57,990 --> 00:01:00,450 That's what you call strain comparison. 15 00:01:00,600 --> 00:01:02,640 So let me comment here. 16 00:01:04,000 --> 00:01:06,250 And then, let's say string. 17 00:01:07,630 --> 00:01:08,770 Comparison. 18 00:01:11,520 --> 00:01:12,150 Comparison. 19 00:01:12,150 --> 00:01:12,810 Yes. 20 00:01:16,480 --> 00:01:17,170 Good. 21 00:01:17,200 --> 00:01:24,940 So in order to compare whether one strain is more than the other, JavaScript employs what is known 22 00:01:24,940 --> 00:01:28,990 as dictionary or lexical graphical order. 23 00:01:29,500 --> 00:01:34,870 In other words, strings are compared by letter by letter. 24 00:01:34,900 --> 00:01:37,800 Let's see ways of comparing strings. 25 00:01:37,810 --> 00:01:41,090 For the meantime, let's compare letters together. 26 00:01:41,110 --> 00:01:44,080 So let's consider that log this. 27 00:01:44,290 --> 00:01:58,480 And now let's say that that's a less than B, if I save it, I got true because B comes after A. 28 00:01:58,510 --> 00:02:02,950 So it means that B is more than A the first point. 29 00:02:03,040 --> 00:02:10,870 The next point is, let me copy this one and then let's compare with the same letters, but different. 30 00:02:11,550 --> 00:02:12,510 Sheep, for example. 31 00:02:12,520 --> 00:02:14,880 One is uppercase and one is lowercase. 32 00:02:14,880 --> 00:02:16,020 So let's comment on this one. 33 00:02:16,020 --> 00:02:22,610 This one means that the the one that comes after the other is heavier. 34 00:02:22,620 --> 00:02:31,650 So A is a list followed by B, C, D, and the rest with Z is the highest if you are comparing the both 35 00:02:31,650 --> 00:02:33,330 lowercase together. 36 00:02:33,330 --> 00:02:41,610 So when I say Z here or sorry lowercase z here, I go through because Z is more than a like the first 37 00:02:41,610 --> 00:02:42,210 note. 38 00:02:42,210 --> 00:02:48,000 But the second point is that we see that they are of the same type, but one is uppercase and one is 39 00:02:48,000 --> 00:02:52,080 lowercase, so a is less than a uppercase. 40 00:02:52,110 --> 00:02:55,620 A Well, this is false. 41 00:02:55,620 --> 00:02:57,090 Always lowercase. 42 00:02:57,090 --> 00:03:00,090 R Heavier than the uppercase. 43 00:03:00,600 --> 00:03:03,000 Even there be more about this. 44 00:03:03,030 --> 00:03:04,970 I will leave some documentation for it. 45 00:03:04,990 --> 00:03:06,630 Read more about the order. 46 00:03:06,630 --> 00:03:13,890 How they appear in a certain scale, but for the mean time give you some simple fact about this logic. 47 00:03:14,160 --> 00:03:19,410 So the next point need to bear in mind is let's have one example here. 48 00:03:19,440 --> 00:03:25,230 Let's say I have blue and then here is GLY. 49 00:03:27,170 --> 00:03:27,950 Glee. 50 00:03:29,420 --> 00:03:32,480 Before we safe and sound. 51 00:03:33,050 --> 00:03:35,630 Can you tell me what the answer? 52 00:03:36,420 --> 00:03:37,110 Okay. 53 00:03:37,230 --> 00:03:38,190 Pause here. 54 00:03:38,460 --> 00:03:42,060 Let me give you some facts before we come back to this. 55 00:03:42,240 --> 00:03:49,890 Well, point number one is, bear in mind is that lower cases are more than upper cases. 56 00:03:50,220 --> 00:03:50,810 Okay. 57 00:03:50,820 --> 00:03:58,260 And we can determine where they are inside the internal encoding table of JavaScript. 58 00:03:58,260 --> 00:03:59,640 And that's a unique code. 59 00:03:59,910 --> 00:04:08,340 So if we want to learn more about this, we can go online and see which are where in the table or the 60 00:04:08,340 --> 00:04:10,470 internal table of JavaScript. 61 00:04:10,500 --> 00:04:11,800 That's this lettuce. 62 00:04:11,820 --> 00:04:12,390 Okay. 63 00:04:12,420 --> 00:04:18,120 For the meantime, let me give you the fact the simple way or summarize in a simple way would understand 64 00:04:18,120 --> 00:04:20,760 here without reading those documentation. 65 00:04:20,910 --> 00:04:26,460 So one point again is that lower cases are more than upper cases if they are of the same type. 66 00:04:27,150 --> 00:04:35,610 Point about two is that if they are of the same type, always the lower case is more than the other 67 00:04:35,610 --> 00:04:36,720 as like I said. 68 00:04:36,720 --> 00:04:44,340 And then the order a is the least followed by B, C, D, and the order z is the highest. 69 00:04:45,250 --> 00:04:51,730 So the next point is that if you are checking for letters like this one, like this one. 70 00:04:52,000 --> 00:04:56,190 So the first it would check the first letters on both sides. 71 00:04:56,200 --> 00:04:56,880 Checking. 72 00:04:56,890 --> 00:04:59,740 Yes, it's checking the first letters on both sides. 73 00:05:00,700 --> 00:05:04,150 If one is more than the other, it will return. 74 00:05:04,150 --> 00:05:04,800 True. 75 00:05:04,810 --> 00:05:11,650 But if they are equal you to move the next letter until it returns true or false. 76 00:05:12,130 --> 00:05:19,780 And lowercase are always more than the uppercase letters of the same type, because the lowercase character 77 00:05:19,780 --> 00:05:24,760 has a greater index in the internal encoding table of JavaScript. 78 00:05:24,940 --> 00:05:26,260 That is a unicode. 79 00:05:26,470 --> 00:05:31,540 So if both strains end at the same length, then they are equal. 80 00:05:31,570 --> 00:05:35,770 Otherwise the longer string is more. 81 00:05:36,490 --> 00:05:39,980 So let me let me let me show you that grammatically over here. 82 00:05:40,000 --> 00:05:42,910 First, I'm going to check both sides. 83 00:05:43,030 --> 00:05:45,190 Let's see if want to check. 84 00:05:45,190 --> 00:05:47,500 We have G and we have G. 85 00:05:47,620 --> 00:05:50,130 They are the same type, so they are equal. 86 00:05:50,140 --> 00:05:51,610 So you move the next letter. 87 00:05:51,730 --> 00:05:53,830 Small error and more error. 88 00:05:53,860 --> 00:05:56,110 Yes, they are equal now. 89 00:05:56,110 --> 00:05:58,090 Small and then small. 90 00:05:58,090 --> 00:06:00,790 E which one is heavier? 91 00:06:01,150 --> 00:06:01,870 Well. 92 00:06:02,760 --> 00:06:09,360 E comes after all or comes after E in the case. 93 00:06:11,050 --> 00:06:22,390 Or comes after e meaning that or is heavier than E therefore now this one is true. 94 00:06:22,630 --> 00:06:25,870 True here, and this one is false. 95 00:06:26,080 --> 00:06:35,950 So it means that glow is not less than glee because o is more than E, therefore the whole logic will 96 00:06:35,950 --> 00:06:38,670 exit and when to return the answer. 97 00:06:38,680 --> 00:06:43,870 So for this one, if I save it, for me it's going to return. 98 00:06:43,870 --> 00:06:46,960 False moment of truth. 99 00:06:47,770 --> 00:06:49,360 Yes, indeed. 100 00:06:49,360 --> 00:06:51,220 We have false over here. 101 00:06:51,930 --> 00:06:53,850 So that is it about that. 102 00:06:54,060 --> 00:06:59,480 So if I change, let's say this one to also us. 103 00:06:59,490 --> 00:07:00,060 Oh. 104 00:07:01,070 --> 00:07:03,110 Now we have uppercase. 105 00:07:03,260 --> 00:07:04,790 Then we have lowercase. 106 00:07:04,820 --> 00:07:10,280 Which one is going to retain the same thing or is heavier than this one? 107 00:07:10,280 --> 00:07:12,470 So same as what force? 108 00:07:12,470 --> 00:07:15,380 If I save it, I still see force. 109 00:07:15,560 --> 00:07:20,150 All right, so that's the basic explanation about how we can compare string together. 110 00:07:20,150 --> 00:07:21,200 So we are done with that. 111 00:07:21,200 --> 00:07:24,830 So let me bring it back to Glow and this one to us, Glow. 112 00:07:25,490 --> 00:07:25,940 Okay. 113 00:07:26,210 --> 00:07:31,110 The next comparison is comparison of different types. 114 00:07:31,130 --> 00:07:33,530 Let's see how we can compare. 115 00:07:33,950 --> 00:07:36,830 Compare string of different. 116 00:07:37,610 --> 00:07:38,390 Types. 117 00:07:38,720 --> 00:07:40,190 How is it possible? 118 00:07:40,430 --> 00:07:49,120 Well, when comparing values of different types, JavaScript convert the values to numbers and even 119 00:07:49,130 --> 00:07:49,760 more. 120 00:07:49,790 --> 00:07:51,320 And the numbers better. 121 00:07:51,320 --> 00:07:58,730 Understand this and remember that one to aim for this one we have talk about it about the equality, 122 00:07:58,730 --> 00:08:03,110 the double, and then the triple equals sign, how it works. 123 00:08:03,110 --> 00:08:05,480 So let's compare with different types. 124 00:08:05,480 --> 00:08:07,430 So let's console.log. 125 00:08:07,610 --> 00:08:13,280 Let's say a is more than I mean. 126 00:08:13,310 --> 00:08:14,360 Okay, let me say. 127 00:08:14,360 --> 00:08:17,510 Yeah, A is more than two. 128 00:08:17,630 --> 00:08:18,410 Let's see. 129 00:08:19,010 --> 00:08:20,090 No is force. 130 00:08:21,150 --> 00:08:23,190 A is never more than two here. 131 00:08:23,190 --> 00:08:25,440 So it's false here. 132 00:08:25,740 --> 00:08:27,170 So true. 133 00:08:27,180 --> 00:08:30,930 So if you're trying to compare this one, how is it possible? 134 00:08:30,930 --> 00:08:32,490 Why do we got false? 135 00:08:32,490 --> 00:08:36,809 Because two is more than a that's the first scenario here. 136 00:08:36,929 --> 00:08:45,690 The second scenario here is if you are trying to compare a string and number, again, let's see with 137 00:08:45,690 --> 00:08:46,800 this example. 138 00:08:47,430 --> 00:08:53,520 So let's say that I have here as five and then here also as five. 139 00:08:54,250 --> 00:08:57,880 How is it going to happen for this one if I save it? 140 00:08:57,970 --> 00:09:02,920 It is false because five is more than what this file. 141 00:09:02,950 --> 00:09:09,640 By default OC by default JavaScript behind this scene doing the convention for us. 142 00:09:10,860 --> 00:09:11,110 Okay. 143 00:09:11,340 --> 00:09:14,440 And would that be more about why this is okay? 144 00:09:14,460 --> 00:09:17,250 So if I also bring let's say. 145 00:09:18,210 --> 00:09:23,670 Though we quoted, what would be the answer going to be true if I say it? 146 00:09:23,820 --> 00:09:32,670 I got true because for equal sign it compared the values without taking into consideration the data 147 00:09:32,670 --> 00:09:34,350 type of the value. 148 00:09:34,740 --> 00:09:40,230 Because the data type of five is a string and this five is a number. 149 00:09:40,770 --> 00:09:45,680 So if we want to have strict comparison, we use triple equal two. 150 00:09:45,690 --> 00:09:49,920 Now I got false because a string can never be more. 151 00:09:49,920 --> 00:09:51,750 Cannot be equal to what five? 152 00:09:52,080 --> 00:09:53,880 There's one word in JavaScript. 153 00:09:53,880 --> 00:09:57,540 How can you compare a string to a string with a sign? 154 00:09:57,540 --> 00:10:03,510 And you say it is true, but behind the scene is doing the implicit I mean convention for us. 155 00:10:04,830 --> 00:10:10,440 Then what about comparing I mean Boolean values, comparing boolean values. 156 00:10:10,440 --> 00:10:13,860 So let's say comment out, not remove it. 157 00:10:13,890 --> 00:10:20,010 Comment out this and now let's compare Boolean values. 158 00:10:22,120 --> 00:10:24,310 So console.log. 159 00:10:25,420 --> 00:10:26,950 Is true. 160 00:10:29,160 --> 00:10:30,300 Equal to. 161 00:10:31,300 --> 00:10:32,060 One. 162 00:10:32,080 --> 00:10:32,890 Let's see. 163 00:10:33,600 --> 00:10:35,250 Yes, it is one. 164 00:10:35,340 --> 00:10:39,180 Because remember, if I bring triple equal to. 165 00:10:40,270 --> 00:10:43,360 I get force if I bring double equal to. 166 00:10:44,280 --> 00:10:47,910 I go true because always true. 167 00:10:48,300 --> 00:10:48,750 Always. 168 00:10:48,750 --> 00:10:57,540 What's not a false value is a true value and true value values start from one one, two, three, four 169 00:10:57,570 --> 00:11:00,220 and zero is what force value. 170 00:11:00,300 --> 00:11:03,180 So if I provide f here, force here. 171 00:11:03,950 --> 00:11:06,560 Frost here is going to be improve. 172 00:11:06,560 --> 00:11:11,900 Our force is always assigned a zero, so force is equal to zero meaning force. 173 00:11:11,960 --> 00:11:14,690 Okay, that's about a boolean comparison. 174 00:11:14,900 --> 00:11:24,920 So what about the last one is comparing with null and undefined now and undefined, let's say compare 175 00:11:25,040 --> 00:11:28,720 null and undefined. 176 00:11:28,730 --> 00:11:29,510 Let's see. 177 00:11:29,510 --> 00:11:31,340 Console.log. 178 00:11:31,670 --> 00:11:33,920 Let's I want to compare that now. 179 00:11:35,340 --> 00:11:37,890 Equal to undefined. 180 00:11:39,720 --> 00:11:40,510 Let's see. 181 00:11:40,530 --> 00:11:44,720 It is true because these ones have no values. 182 00:11:44,730 --> 00:11:50,070 But to make sure that you have a straight comparison you triple equal to. 183 00:11:50,100 --> 00:11:52,590 In that case, you're going to get false. 184 00:11:53,980 --> 00:11:56,320 So guys, that is simple. 185 00:11:56,320 --> 00:11:59,260 I mean, string comparison we can make. 186 00:11:59,440 --> 00:12:05,320 Well, the next video, let's start with a new topic called numbers.