1
00:00:00,210 --> 00:00:03,810
Before we start, did you try solving the workbook yourself?

2
00:00:03,840 --> 00:00:09,600
If not, please click the link in the resources folder and follow the instructions for this workbook.

3
00:00:10,890 --> 00:00:13,190
Welcome to Workbook 5.10.

4
00:00:13,200 --> 00:00:17,670
In this workbook, the user must keep rolling dice until they roll doubles.

5
00:00:17,700 --> 00:00:22,320
Task one is to make a function that returns a random number between one and six.

6
00:00:22,320 --> 00:00:25,320
Let's copy the description over here.

7
00:00:26,930 --> 00:00:28,750
So public static.

8
00:00:28,760 --> 00:00:33,980
The return type is int because this function will return a random number.

9
00:00:34,070 --> 00:00:37,040
It does not expect any values to be passed in.

10
00:00:37,040 --> 00:00:40,700
All it's going to do is roll a dice between one and six.

11
00:00:40,730 --> 00:00:45,590
You'll remember from the functions section, the familiar math random function.

12
00:00:45,590 --> 00:00:51,380
What it does is it returns a random decimal greater than or equal to zero and less than one.

13
00:00:51,380 --> 00:00:57,050
So a value in the range of 0 to 0.9999999.

14
00:00:57,050 --> 00:01:03,800
If we multiply the result by six, the minimum value would still be zero, but the maximum decimal that

15
00:01:03,800 --> 00:01:09,830
could be returned from that random will be now scaled to 5.9999.

16
00:01:09,830 --> 00:01:14,540
So this current code will return a random decimal.

17
00:01:17,290 --> 00:01:19,510
Inside this range.

18
00:01:22,040 --> 00:01:28,280
But we want to roll a dice between one and six so we know our minimum needs to be scaled up to one.

19
00:01:28,310 --> 00:01:31,340
Here we'll say a random decimal plus equals one.

20
00:01:31,670 --> 00:01:38,180
By virtue of doing that, assuming a random decimal ended up being the minimum, here it becomes one.

21
00:01:38,360 --> 00:01:44,180
And now assuming that random decimal ended up being the maximum possible value that this code could

22
00:01:44,180 --> 00:01:48,950
return, now it would be 6.99999.

23
00:01:50,560 --> 00:01:54,250
And now if we typecast this decimal before returning it.

24
00:01:56,790 --> 00:02:03,240
Given that this can be any value between one and 6.999, assuming that it was the minimum, it would

25
00:02:03,240 --> 00:02:04,140
still be one.

26
00:02:04,140 --> 00:02:10,280
But if it's the maximum, the decimal would just get cut off and you would get a dice roll between 1

27
00:02:10,280 --> 00:02:11,100
to 6.

28
00:02:11,430 --> 00:02:12,690
All right.

29
00:02:13,630 --> 00:02:16,420
So that was task number one.

30
00:02:17,340 --> 00:02:24,000
Task number two is to call the roll dice function twice and store the values and variables Dice one

31
00:02:24,000 --> 00:02:27,930
and dice two, then print each dice as follows.

32
00:02:28,240 --> 00:02:35,430
So dice one is equal to random number, and dice two is equal to random number.

33
00:02:35,670 --> 00:02:38,340
We seem to already have the print statements over here.

34
00:02:38,340 --> 00:02:43,070
That is perfect and we're off to a great start.

35
00:02:43,080 --> 00:02:47,910
Task number three is to set up a loop that keeps running while the two dice aren't the same.

36
00:02:47,910 --> 00:02:52,560
And during each run we roll the dice and print both values.

37
00:02:52,560 --> 00:03:01,470
So here we'll say while dice one is not equal to dice two, So while the two dice are not the same,

38
00:03:01,470 --> 00:03:04,440
we need to keep running the loop until they are.

39
00:03:04,440 --> 00:03:05,140
And you know what?

40
00:03:05,160 --> 00:03:09,000
Before I continue, I want to call this roll dice instead.

41
00:03:09,030 --> 00:03:11,730
That seems more intuitive to me.

42
00:03:12,430 --> 00:03:17,170
And so whenever this wild loop runs, we need to update our dice rolls.

43
00:03:17,170 --> 00:03:21,850
So here we'll say dice one is equal to a new roll of the dice.

44
00:03:22,240 --> 00:03:31,000
Dice two is equal to a new roll of the dice, and then we can print the updated dice values.

45
00:03:34,030 --> 00:03:39,270
So this wild loop is going to keep running until the dice eventually equal each other.

46
00:03:39,280 --> 00:03:45,730
Eventually it will break and once the while loop breaks, we know that the dice ended up equaling each

47
00:03:45,730 --> 00:03:46,060
other.

48
00:03:46,060 --> 00:03:52,810
They rolled doubles so we can print out of no success or something, or we'll just print you rolled

49
00:03:52,810 --> 00:03:53,680
doubles.

50
00:03:57,250 --> 00:03:59,210
All right, Let us visualize the runtime.

51
00:03:59,230 --> 00:04:00,880
I will put.

52
00:04:01,850 --> 00:04:05,030
Two breakpoints over here and one over here.

53
00:04:05,030 --> 00:04:06,920
And we'll start visualizing.

54
00:04:13,240 --> 00:04:20,709
So when you call a roll dice, this code can return any decimal in the range of 0 to 5.999.

55
00:04:20,740 --> 00:04:27,340
In this case, it returns a decimal of 1.8, add one to it, it becomes 2.8.

56
00:04:27,550 --> 00:04:29,530
Convert the decimal to an integer.

57
00:04:29,530 --> 00:04:33,370
We get a value of two The second dice roll.

58
00:04:33,370 --> 00:04:34,810
Let's step into it.

59
00:04:35,650 --> 00:04:41,170
So this once again can return any number between zero and less than six.

60
00:04:41,920 --> 00:04:44,950
That returns a value of 3.9 and one.

61
00:04:44,950 --> 00:04:50,140
It becomes 4.9 typecast to an end and we have a dice roll of four.

62
00:04:52,910 --> 00:05:00,230
Because dice one does not equal dice two this while loop is going to run, prompting them to roll dice

63
00:05:00,230 --> 00:05:00,920
again.

64
00:05:00,920 --> 00:05:07,430
So entering roll dice again, This can return anything between zero and less than six.

65
00:05:07,610 --> 00:05:10,580
It returns 3.21.

66
00:05:10,610 --> 00:05:11,600
That's four.

67
00:05:11,630 --> 00:05:13,610
Convert that to an integer.

68
00:05:14,640 --> 00:05:17,280
So here we have a dice roll of four.

69
00:05:17,970 --> 00:05:20,040
Let's hope we get four again.

70
00:05:22,630 --> 00:05:24,250
And that is just perfect.

71
00:05:24,250 --> 00:05:26,820
Converting 4.9 to an integer.

72
00:05:26,830 --> 00:05:29,470
We get another dice roll of four.

73
00:05:31,860 --> 00:05:32,190
Here.

74
00:05:32,190 --> 00:05:33,420
We print the first dice.

75
00:05:33,420 --> 00:05:38,470
Here we print the second dice because dice one equals dice two.

76
00:05:38,490 --> 00:05:39,960
This evaluates the false.

77
00:05:39,960 --> 00:05:42,420
So the while loop is not going to run anymore.

78
00:05:42,450 --> 00:05:45,450
It will break and then it's going to print.

79
00:05:45,450 --> 00:05:47,130
You rolled doubles.