1
00:00:00,530 --> 00:00:02,660
OK so let's start with the first one here.

2
00:00:02,670 --> 00:00:06,330
Print all the numbers between negative 10 and 19.

3
00:00:06,600 --> 00:00:10,560
So before we actually start writing code we need to make our files.

4
00:00:10,560 --> 00:00:12,510
So I have a simple Tim file

5
00:00:15,330 --> 00:00:18,090
and I need to create a script to connect.

6
00:00:18,300 --> 00:00:19,950
So let's save our script.

7
00:00:20,130 --> 00:00:21,250
Let's call it loops.

8
00:00:21,400 --> 00:00:31,330
Yes save that and then I'll add an alert because I always want to make sure they're connected.

9
00:00:31,950 --> 00:00:39,700
Go back to wild study DML and then just link to that script which was loops that.

10
00:00:39,720 --> 00:00:41,230
Yes.

11
00:00:41,280 --> 00:00:46,620
So now if we go and open that up we should get our nice alert.

12
00:00:46,710 --> 00:00:47,780
Great.

13
00:00:47,790 --> 00:00:49,360
So let's tackle the first one.

14
00:00:49,370 --> 00:00:53,360
Print all numbers between negative 10 and 19.

15
00:00:54,540 --> 00:00:56,800
So we're going to start with a WHILE loop.

16
00:00:57,180 --> 00:01:04,530
We're going to start with the variable var let's say counter starts at negative 10 then we'll just have

17
00:01:04,530 --> 00:01:13,660
a wild loop where we're checking while counter is less than 20.

18
00:01:14,370 --> 00:01:22,580
Cancel that log counter and then we'll add 1 to counter just like that.

19
00:01:22,590 --> 00:01:24,220
So we started negative 10.

20
00:01:24,540 --> 00:01:29,400
We printed out we add 1 while Kountry is less than 20.

21
00:01:29,430 --> 00:01:35,380
We could also refactor this to be while it's less than or equal to 19.

22
00:01:35,430 --> 00:01:40,470
Either one works in a do this one just for variety sake so save.

23
00:01:40,680 --> 00:01:50,160
And let's go at a con. that log up top just to make it clear we're printing all numbers between negative

24
00:01:50,160 --> 00:01:55,520
10 and 19 save and run this.

25
00:01:55,560 --> 00:01:57,880
So will refresh the page.

26
00:01:58,500 --> 00:02:04,170
Don't see anything because it's all on the console and you can see we get all numbers between negative

27
00:02:04,170 --> 00:02:06,040
10 and 19.

28
00:02:06,300 --> 00:02:09,210
Make sure it includes 19 negative 10.

29
00:02:09,210 --> 00:02:10,610
Great.

30
00:02:10,680 --> 00:02:15,760
So the next challenge is to print out all even numbers between 10 and 40.

31
00:02:16,140 --> 00:02:20,110
So I'm just going to copy this and modify it just a little bit.

32
00:02:20,190 --> 00:02:28,400
So printing all even numbers between 10 and 40 save.

33
00:02:28,770 --> 00:02:37,590
So we'll start with our counter just equal to 10 while counter is less than 41 or less than or equal

34
00:02:37,590 --> 00:02:38,970
to 40.

35
00:02:38,970 --> 00:02:40,380
Let's do it this way.

36
00:02:40,650 --> 00:02:43,390
We're going to print it out only if it's even.

37
00:02:43,650 --> 00:02:45,570
So there's a few ways to do this.

38
00:02:45,630 --> 00:02:50,760
The first one is that we always print it out but we count by twos.

39
00:02:51,330 --> 00:02:53,770
So this means that we start at 10.

40
00:02:53,820 --> 00:02:58,560
Then we add then we print 10 out and we add two and then we are at 12.

41
00:02:58,730 --> 00:03:01,010
So then we print out 12 and then we add two.

42
00:03:01,020 --> 00:03:04,180
So that's one way of doing it just to make sure that works.

43
00:03:04,230 --> 00:03:12,290
Let's refresh open the console and you can see printing all evens between 10 and 40.

44
00:03:12,390 --> 00:03:13,980
And that works fine.

45
00:03:14,010 --> 00:03:16,230
So there's another way that we could have written this.

46
00:03:16,500 --> 00:03:18,910
And I'll just copy this to show you.

47
00:03:19,470 --> 00:03:20,740
We could write it this way.

48
00:03:21,000 --> 00:03:24,240
So we loop through for every number.

49
00:03:24,270 --> 00:03:29,400
So we don't count by twos and then we're going to have an if statement in here to check if a number

50
00:03:29,400 --> 00:03:30,200
is even.

51
00:03:30,510 --> 00:03:36,180
And that looks like if counter mod 2 is zero.

52
00:03:36,390 --> 00:03:42,870
So that's how you tell for numbers even if it's evenly divisible by two then we'll print it out and

53
00:03:42,870 --> 00:03:44,340
then we'll just add one.

54
00:03:44,820 --> 00:03:49,920
So this way is shorter and it's a little more efficient because this loop is only going to run half

55
00:03:49,920 --> 00:03:53,750
as many times as this one because we're counting by twos.

56
00:03:53,940 --> 00:03:58,700
So we never run this loop for the odd numbers versus this one down here.

57
00:03:58,950 --> 00:04:05,090
If we start with 10 if counter 2 is zero it is constant at like 10.

58
00:04:05,220 --> 00:04:06,140
We add 1.

59
00:04:06,330 --> 00:04:07,840
So now we do it for 11.

60
00:04:08,010 --> 00:04:13,200
So this code is evaluated is 11 divisible by 2 and it's not.

61
00:04:13,230 --> 00:04:18,130
So this isn't printed out but the code in the loop is still run every single time.

62
00:04:18,300 --> 00:04:23,940
So there is one advantage of this set up here which is it will always print out the even numbers no

63
00:04:23,940 --> 00:04:27,750
matter what number we start it versus this one.

64
00:04:27,840 --> 00:04:33,520
If we started at 11 it's always going to just add to to that base number.

65
00:04:33,540 --> 00:04:39,900
So we'll have 11 13 15 which aren't even but this one is actually checking if they are even.

66
00:04:40,080 --> 00:04:44,790
So I'm going to comment that out for now and let's go with just the short version which for insert the

67
00:04:44,790 --> 00:04:48,980
even numbers between 10 and 40 as we see here.

68
00:04:50,160 --> 00:04:56,310
So next up we have print all odd numbers between 300 and 333.

69
00:04:56,310 --> 00:04:59,060
So again it's very very similar to this.

70
00:04:59,100 --> 00:05:11,910
I'm just going to copy all of this again and change this so printing all odd numbers between 300 and

71
00:05:11,910 --> 00:05:18,080
333 and then we're going to start with counter at 300.

72
00:05:18,090 --> 00:05:21,060
So this one won't work because we're starting at 300.

73
00:05:21,060 --> 00:05:24,730
If we add two there will be 300 two and that will count by evens.

74
00:05:24,780 --> 00:05:28,880
So I'm going to get rid of it and let's use the slightly longer way.

75
00:05:29,220 --> 00:05:33,710
So to check if something is odd We want to make sure that it's not divisible by 2.

76
00:05:33,870 --> 00:05:41,010
So that looks like if counter Montu is not equal to zero then we'll print out counter and the other

77
00:05:41,010 --> 00:05:46,920
thing we need to change is this loop is going to start at 300 and we're checking if it's less than 40

78
00:05:46,930 --> 00:05:46,960
.

79
00:05:46,980 --> 00:05:49,110
So right now this code won't even run.

80
00:05:49,350 --> 00:05:57,980
So we want to make this 333 So let's save and refresh and you can see we get all the odd numbers 3 or

81
00:05:57,990 --> 00:06:01,560
1 all the way to 333.

82
00:06:01,560 --> 00:06:10,170
So the last one here is to print all numbers divisible by five and three that are between 5 and 50.

83
00:06:10,230 --> 00:06:13,440
So going to copy are set up one more time.

84
00:06:13,560 --> 00:06:18,990
So this time I'm going to cancel that log printing all numbers divisible by

85
00:06:22,080 --> 00:06:31,350
5 and 3 between 5 and 50.

86
00:06:31,410 --> 00:06:38,460
So to do that we're going to start with our counter at 5 and it's going to go until 50.

87
00:06:39,720 --> 00:06:45,200
And our logic here is not checking if it's not divisible by 2 which is what we have here.

88
00:06:45,750 --> 00:06:50,930
What we want to do is check if it is divisible by 5 and divisible by 3.

89
00:06:51,210 --> 00:07:04,800
So that's going to look like counter maade 5 equals zero and counter maade three equals zero and that's

90
00:07:04,800 --> 00:07:05,520
it.

91
00:07:05,520 --> 00:07:12,470
So both of these need to be true divisible by five evenly and 3 in order for us to printed out.

92
00:07:12,810 --> 00:07:13,890
So that's all we need to do.

93
00:07:13,950 --> 00:07:20,190
Let's go ahead and refresh our browser and you can see we get all numbers that are divisible both by

94
00:07:20,190 --> 00:07:25,370
5 and 3 that are between 5 and 50 and there's only three of them.

95
00:07:25,380 --> 00:07:27,740
All right so that's it for this while loops problem set.