1 00:00:00,390 --> 00:00:06,900 You might also get a task like this, remove all duplicates in their right, which basically means if 2 00:00:06,900 --> 00:00:12,330 you have an array of numbers and you have, for example, one one tool, you need to live on the one 3 00:00:12,330 --> 00:00:12,930 and tongue. 4 00:00:16,220 --> 00:00:19,310 I see here three different ways to solve our problem. 5 00:00:19,550 --> 00:00:21,380 Let's try with the best solution. 6 00:00:21,650 --> 00:00:27,860 For example, we can create here a function unique array, and we're getting here our way to remove 7 00:00:27,860 --> 00:00:28,670 all duplicates. 8 00:00:28,970 --> 00:00:30,290 And here what we want to do. 9 00:00:30,290 --> 00:00:34,520 We want to return and jewelry and we want to spread inside. 10 00:00:34,520 --> 00:00:37,730 And you said and were bison inside the rate. 11 00:00:38,030 --> 00:00:43,730 If you don't know what certain JavaScript is, it's an object which allow you to store unique values 12 00:00:43,730 --> 00:00:44,720 of any type. 13 00:00:45,020 --> 00:00:50,840 This means that if we're right in here and you said and were passing inside out, for example, one 14 00:00:50,840 --> 00:00:52,400 one tomb were hidden. 15 00:00:52,400 --> 00:00:58,550 And as you can see, we have the set only from one and two because inside those set elements can be 16 00:00:58,550 --> 00:00:59,240 duplicated. 17 00:00:59,450 --> 00:01:05,330 This is why, as you can see if we will spread on your set and put it in the new array to convert said 18 00:01:05,330 --> 00:01:05,900 back to us. 19 00:01:06,320 --> 00:01:08,300 We will get our unique elements. 20 00:01:08,540 --> 00:01:14,210 And actually not a lot of people know about this solution, but this is the best solution because it 21 00:01:14,210 --> 00:01:15,680 is, first of all, a single line. 22 00:01:15,860 --> 00:01:17,840 Secondly, it is really performant. 23 00:01:18,110 --> 00:01:20,390 If you don't know this solution, it's not bad. 24 00:01:20,540 --> 00:01:23,030 You can always build this logic on your own. 25 00:01:23,270 --> 00:01:28,940 The most important part that even for loop here, if you are using for reach for Ray is not that bad. 26 00:01:29,240 --> 00:01:30,190 Let's check this out. 27 00:01:30,200 --> 00:01:35,600 For example, we have here the same function, unique array, and we have one two right here, a loop. 28 00:01:35,780 --> 00:01:39,260 And of course, we need to store our result in additional property. 29 00:01:39,440 --> 00:01:43,520 So let's make here result, which will be our unique right now. 30 00:01:43,520 --> 00:01:48,650 Here, I want to look through every single element of our array with for each function. 31 00:01:48,890 --> 00:01:52,850 And here we're getting our item as every element of our array. 32 00:01:53,120 --> 00:01:58,880 Now what we want to check here, if we already have the system inside our result, so we can check here 33 00:01:58,880 --> 00:02:00,890 result dot includes. 34 00:02:01,130 --> 00:02:06,800 And if you don't know, includes check if we have the element inside in the rape and we want to pass 35 00:02:06,800 --> 00:02:07,940 inside our item. 36 00:02:08,060 --> 00:02:10,490 So this will return true if it includes. 37 00:02:10,730 --> 00:02:14,120 But actually, we must put here bank to have a negation. 38 00:02:14,330 --> 00:02:19,520 And if it does not include this element inside the array, then we want to push it to our result. 39 00:02:19,760 --> 00:02:22,100 So result Bush and here the item. 40 00:02:22,490 --> 00:02:28,580 So as you can see, even for each look here is not that bad because it is isolated inside our function 41 00:02:28,730 --> 00:02:34,310 where simpler looping through every single element and we're pushing our result directly in the new 42 00:02:34,310 --> 00:02:34,760 array. 43 00:02:35,090 --> 00:02:38,030 And of course, the we must return our result. 44 00:02:38,060 --> 00:02:41,330 So here, let's return the result and check if it's working. 45 00:02:41,630 --> 00:02:44,420 So here is our function unique array one one two. 46 00:02:44,540 --> 00:02:50,600 And as you can see, we're getting one and two back, but obviously our function won't work with objects 47 00:02:50,600 --> 00:02:51,620 or raise inside. 48 00:02:51,770 --> 00:02:53,330 And this is completely normal. 49 00:02:53,540 --> 00:02:59,300 So if you have here an object with a equals one and here you have one more object with eight equals 50 00:02:59,300 --> 00:02:59,590 one. 51 00:02:59,810 --> 00:03:05,390 As you can see, we're getting two elements and this is totally fine because this is two different objects 52 00:03:05,540 --> 00:03:07,100 and we can't compare them. 53 00:03:07,460 --> 00:03:11,030 And actually, we can provide this for each by using reduce. 54 00:03:11,240 --> 00:03:15,860 In this way, people write exactly the same code buttons and more functional way. 55 00:03:15,890 --> 00:03:19,460 So here let's create our function unique array we're getting here. 56 00:03:20,330 --> 00:03:23,750 And one directly to return array reduce. 57 00:03:24,020 --> 00:03:29,090 And here inside, we must pass our function with accumulator and every single element. 58 00:03:29,510 --> 00:03:35,720 So here we have a function and as a default argument we have here, empty array exactly like we had 59 00:03:35,720 --> 00:03:38,960 here were without constant result equals empty array. 60 00:03:39,350 --> 00:03:45,140 Now what we want to do inside, we want to check our accumulator includes, so we're checking our result. 61 00:03:45,260 --> 00:03:48,200 If we have this resulted, array our element. 62 00:03:48,410 --> 00:03:52,460 So if we have it then was simpler to turn accumulator, so we don't change anything. 63 00:03:52,670 --> 00:03:58,580 In the case, we want to push this element to accumulator and we're not using a push, but we're using 64 00:03:58,580 --> 00:03:59,060 spread. 65 00:03:59,360 --> 00:04:04,610 So here I am spreading accumulator and then I imagine our element in this way. 66 00:04:04,610 --> 00:04:06,560 This code is completely functional. 67 00:04:06,710 --> 00:04:11,840 It is easy to understand and we don't have this nested, but here let's load the page and check if it's 68 00:04:11,840 --> 00:04:12,260 working. 69 00:04:12,440 --> 00:04:17,810 As you can see, it still doesn't work with objects, which is totally fine, and it works with primitives 70 00:04:17,810 --> 00:04:20,420 because here one was removed from our rate. 71 00:04:20,750 --> 00:04:25,370 So as you can see, you have three different variants to implement uniqueness in array. 72 00:04:25,370 --> 00:04:29,660 And actually, all these revisions are completely fine to show on the interview.