1
00:00:00,009 --> 00:00:04,400
Let's now talk about the break statement because it's a very,

2
00:00:04,409 --> 00:00:07,119
very powerful statement and we're going to be working with it in

3
00:00:07,449 --> 00:00:09,810
this course. But before

4
00:00:10,170 --> 00:00:11,149
I do that,

5
00:00:12,010 --> 00:00:16,270
I just want to show you a different way of actually printing out

6
00:00:16,889 --> 00:00:20,500
the names in this particular example.

7
00:00:20,799 --> 00:00:25,770
Right now we're saying good morning and then plus and then XX, of course,

8
00:00:25,780 --> 00:00:27,590
being the variable

9
00:00:27,829 --> 00:00:31,229
representing each name in our list.

10
00:00:32,039 --> 00:00:36,558
Another way of writing this would be to do something like this. First of all,

11
00:00:36,699 --> 00:00:39,499
I'm going to remove the uh plus X

12
00:00:40,209 --> 00:00:40,750
OK?

13
00:00:41,490 --> 00:00:44,830
But now I'm gonna come right here at the very beginning,

14
00:00:45,310 --> 00:00:47,549
I'm going to type in F

15
00:00:48,520 --> 00:00:49,220
OK?

16
00:00:49,639 --> 00:00:51,900
And now right here,

17
00:00:52,419 --> 00:00:57,549
I'm going to add my curly braces, not the usual braces, but the curly ones.

18
00:00:57,900 --> 00:00:58,939
And now here

19
00:00:59,209 --> 00:01:01,090
I will simply type in X

20
00:01:01,750 --> 00:01:02,419
OK.

21
00:01:02,729 --> 00:01:07,260
I can run the program and you can see right now we have the exact same results.

22
00:01:07,480 --> 00:01:12,730
This right here is a different and also a more efficient way

23
00:01:12,980 --> 00:01:16,250
of actually printing out

24
00:01:16,370 --> 00:01:21,440
the values of the variables in a list or an array

25
00:01:21,709 --> 00:01:22,730
in a for

26
00:01:22,889 --> 00:01:24,930
or while loop.

27
00:01:25,349 --> 00:01:26,019
All right.

28
00:01:26,300 --> 00:01:29,489
And we're going to be working like this moving forwards.

29
00:01:29,809 --> 00:01:30,529
Now,

30
00:01:31,470 --> 00:01:35,000
the break statement, what exactly is the brake statement

31
00:01:35,330 --> 00:01:40,879
it's used when we want to terminate a loop early.

32
00:01:41,629 --> 00:01:45,730
For example, in this folder that we've seen right now, what it does is that it simply,

33
00:01:45,739 --> 00:01:47,169
it's simply gonna go through

34
00:01:47,910 --> 00:01:51,209
all the names in our list and then print out

35
00:01:51,510 --> 00:01:54,279
uh good morning and then the name of the person, right?

36
00:01:54,529 --> 00:01:56,440
But what if for one reason or the other,

37
00:01:56,449 --> 00:02:02,230
we wanted to terminate the loop as soon as James has been reached,

38
00:02:02,239 --> 00:02:06,250
we don't want to print out a good morning Violetta because we don't like Violetta,

39
00:02:06,379 --> 00:02:06,870
right?

40
00:02:07,040 --> 00:02:11,889
This is where we could use the break statement

41
00:02:12,210 --> 00:02:14,009
to terminate the loop early

42
00:02:14,559 --> 00:02:18,960
and to demonstrate this, I'm gonna write a completely different program. OK? So

43
00:02:19,089 --> 00:02:21,970
let's do this. All right, I'm gonna type in, let's say numbers again.

44
00:02:21,979 --> 00:02:25,539
I'm gonna create a new list right here. Numbers equals

45
00:02:26,139 --> 00:02:26,839
and

46
00:02:27,149 --> 00:02:28,740
I'm gonna put in my

47
00:02:29,589 --> 00:02:30,770
brackets in here

48
00:02:31,080 --> 00:02:38,410
and let's go with a series of numbers. I'm gonna go with 13. Let's go with uh 78, 10

49
00:02:39,389 --> 00:02:42,809
and let's go with 11 and let's add one more

50
00:02:43,139 --> 00:02:44,820
even number 14.

51
00:02:45,259 --> 00:02:45,809
OK.

52
00:02:46,199 --> 00:02:48,169
So we have a list of numbers in here.

53
00:02:48,580 --> 00:02:51,889
And what we want to do right now is we want to create a loop

54
00:02:52,270 --> 00:02:54,339
that will run through all the numbers.

55
00:02:54,350 --> 00:02:59,580
However, once the first even number has been reached,

56
00:02:59,720 --> 00:03:04,690
we want to terminate the loop, meaning that once the number, which is eight,

57
00:03:05,029 --> 00:03:08,529
we're going to end the loop. So it should run four times

58
00:03:08,770 --> 00:03:12,669
the first loop for one, the second loop for three, third loop for seven,

59
00:03:12,679 --> 00:03:14,460
fourth loop for eight.

60
00:03:14,589 --> 00:03:15,860
So think about this, right,

61
00:03:16,029 --> 00:03:20,309
we're gonna create the for loop first and then we're going to introduce the if

62
00:03:20,490 --> 00:03:23,509
statement. So the if statement will check. OK.

63
00:03:23,520 --> 00:03:30,419
Is this number actually even, or is it odd if it's even then break the loop?

64
00:03:30,429 --> 00:03:33,509
Because we found the first even number elses,

65
00:03:34,000 --> 00:03:36,690
if it's not an even number, if it's an odd number,

66
00:03:37,020 --> 00:03:38,419
continue

67
00:03:38,619 --> 00:03:40,940
with the loop. So

68
00:03:41,190 --> 00:03:43,139
how are we going to do this

69
00:03:43,949 --> 00:03:45,399
gonna tap and enter

70
00:03:45,899 --> 00:03:46,160
the

71
00:03:46,479 --> 00:03:47,149
follow up for,

72
00:03:47,880 --> 00:03:48,899
let's say num

73
00:03:49,139 --> 00:03:52,910
OK, no, would represent the, the numbers.

74
00:03:53,119 --> 00:03:56,479
And by the way, I'm not sure if I've mentioned this before, but I think it's,

75
00:03:56,490 --> 00:03:57,320
it's time I do.

76
00:03:57,330 --> 00:03:57,699
So

77
00:03:58,059 --> 00:03:59,830
see, I've only typed in for number.

78
00:03:59,839 --> 00:04:04,169
You can see right now on my screen, Python is already suggesting in numbers

79
00:04:04,289 --> 00:04:06,389
because Python is actually quite smart, right?

80
00:04:06,750 --> 00:04:07,259
So in

81
00:04:07,399 --> 00:04:08,669
this kind of situation right now,

82
00:04:08,679 --> 00:04:11,830
if you're happy with the suggestion that the program has given you,

83
00:04:11,949 --> 00:04:12,330
you can see,

84
00:04:12,630 --> 00:04:13,979
press the tab

85
00:04:14,490 --> 00:04:15,990
a key on your keyboard

86
00:04:16,170 --> 00:04:16,738
and

87
00:04:16,980 --> 00:04:20,640
you will get the exact same result, right? So I've typed, I

88
00:04:22,079 --> 00:04:23,670
do forgive me. I can't talk,

89
00:04:24,019 --> 00:04:25,630
I've typed the tab number

90
00:04:26,440 --> 00:04:31,519
on the tab key on my keyboard. And now I have for num in numbers, I'm gonna add my colon.

91
00:04:31,529 --> 00:04:32,609
Ok. Now

92
00:04:32,929 --> 00:04:36,730
I'm going to add the if statement. And would you look at that?

93
00:04:37,809 --> 00:04:41,989
I promise you. I've actually not typed this program before,

94
00:04:42,100 --> 00:04:43,940
but I think Python is so intelligent.

95
00:04:43,950 --> 00:04:46,459
It already has an idea of what I might be looking for.

96
00:04:46,720 --> 00:04:48,369
Yes, I want if none

97
00:04:49,040 --> 00:04:54,190
and then percentage two equals zero. So what exactly is this, what is going on here?

98
00:04:54,470 --> 00:04:59,390
What this means is that we're going to check if the number that's been pulled out,

99
00:04:59,570 --> 00:05:04,029
if it's divisible by two and the remainder is equal to zero,

100
00:05:04,040 --> 00:05:07,029
then we know for sure that it is an even number.

101
00:05:07,369 --> 00:05:09,399
If you divide seven by two,

102
00:05:09,510 --> 00:05:15,470
you will get 3.5, 3.5 there's always going to be that remainder may have been half.

103
00:05:15,480 --> 00:05:20,179
But when you divide eight by two, the answer is straight up four.

104
00:05:20,410 --> 00:05:24,799
It's not 4.1 it's not 4.2 it's not 4.5, it is four.

105
00:05:24,809 --> 00:05:30,049
So this is how we can check if the number is actually even.

106
00:05:30,170 --> 00:05:30,790
So

107
00:05:31,079 --> 00:05:33,899
if the number is, in fact, even what do we do,

108
00:05:34,149 --> 00:05:36,070
let's say print,

109
00:05:36,730 --> 00:05:37,510
OK.

110
00:05:38,250 --> 00:05:41,690
And now I'm going to add the F string.

111
00:05:42,600 --> 00:05:45,709
OK? And now the actual string itself

112
00:05:45,890 --> 00:05:49,459
found the first even

113
00:05:49,940 --> 00:05:51,070
number.

114
00:05:51,980 --> 00:05:57,850
OK, let's add my comma. And now I want to display the actual number, curly braces.

115
00:05:57,890 --> 00:06:00,839
And what is it gonna be? It is going to be numb.

116
00:06:01,940 --> 00:06:03,160
OK.

117
00:06:03,500 --> 00:06:04,480
Awesome.

118
00:06:04,910 --> 00:06:05,440
So

119
00:06:06,130 --> 00:06:07,320
we've added what

120
00:06:07,470 --> 00:06:10,140
the program should do if the number is, in fact,

121
00:06:10,779 --> 00:06:16,959
an even number Prince says, OK, we found the first number and now break the loop,

122
00:06:16,980 --> 00:06:19,350
we don't need the loop to want anymore.

123
00:06:19,359 --> 00:06:22,920
Break it. It's over. We found the first even number we're getting out of here.

124
00:06:23,779 --> 00:06:24,859
Else.

125
00:06:26,339 --> 00:06:29,619
Make sure your tabs. Remember the tabulation is extremely important.

126
00:06:29,730 --> 00:06:34,679
If else must be on the same tab right there, the same, the same indentation, right?

127
00:06:34,950 --> 00:06:35,299
So

128
00:06:37,029 --> 00:06:39,929
simply print out, let's just say print,

129
00:06:40,760 --> 00:06:42,010
um,

130
00:06:42,350 --> 00:06:44,940
let me add my brackets and then my coats

131
00:06:45,630 --> 00:06:48,130
still looking

132
00:06:49,070 --> 00:06:51,140
for that even

133
00:06:51,489 --> 00:06:52,239
number.

134
00:06:53,299 --> 00:06:53,940
And

135
00:06:54,589 --> 00:06:55,170
there it is

136
00:06:56,089 --> 00:06:56,679
OK.

137
00:06:57,089 --> 00:06:58,470
Let's go ahead right now,

138
00:06:58,970 --> 00:07:01,910
run the program and there it is

139
00:07:02,390 --> 00:07:04,179
still looking for that even number,

140
00:07:04,190 --> 00:07:06,589
still looking for that even numbers looking for that even number.

141
00:07:06,600 --> 00:07:11,649
Oh, look, we found the first even number and the number is eight.

142
00:07:12,140 --> 00:07:16,869
This is the use of the break statement.

143
00:07:17,309 --> 00:07:24,709
Now let's use it in a while loop now to do this, I'm gonna come all the way down here

144
00:07:25,239 --> 00:07:31,980
and let's create a very simple program that will ask the user to type in something.

145
00:07:32,339 --> 00:07:38,980
And as long as or type in a particular letter and as long as the letter isn't equal to Q,

146
00:07:39,339 --> 00:07:41,019
then just keep asking

147
00:07:41,230 --> 00:07:44,100
the user for a new letter.

148
00:07:44,359 --> 00:07:44,899
OK?

149
00:07:45,179 --> 00:07:45,640
So

150
00:07:45,850 --> 00:07:47,950
that's basically the condition that needs to be satisfied.

151
00:07:47,959 --> 00:07:54,190
So while the user is typing in AB CD, ef as long as it's not Q,

152
00:07:54,290 --> 00:07:57,920
keep asking the user to input a new letter. So

153
00:07:58,350 --> 00:08:00,920
I'm going to say while true

154
00:08:02,630 --> 00:08:06,130
what this does right now, this is a very simple function

155
00:08:06,390 --> 00:08:08,130
or loop in Python

156
00:08:08,290 --> 00:08:13,450
that automatically has created a condition that is always true.

157
00:08:13,709 --> 00:08:17,910
Unless something else happens. Remember that with the wild loops,

158
00:08:18,040 --> 00:08:19,890
there needs to be a particular condition

159
00:08:20,049 --> 00:08:25,089
that must be continually satisfied in order for the loop to actually run

160
00:08:25,190 --> 00:08:30,130
and then it must be terminated once a very specific condition has been met. So

161
00:08:30,399 --> 00:08:32,500
we're going to assume right now that

162
00:08:33,289 --> 00:08:35,030
the condition is always true.

163
00:08:35,479 --> 00:08:39,030
And now I'm going to type in user input,

164
00:08:39,330 --> 00:08:41,539
this is going to be the variable

165
00:08:41,789 --> 00:08:43,109
that will represent

166
00:08:43,330 --> 00:08:44,469
the letter

167
00:08:44,669 --> 00:08:46,869
that the user will actually type in. So

168
00:08:47,059 --> 00:08:49,750
I'm gonna say user input equals and now

169
00:08:50,270 --> 00:08:51,210
input,

170
00:08:51,400 --> 00:08:55,390
remember the function input, which will now ask the user to type in something. So

171
00:08:56,059 --> 00:08:57,080
I'm gonna say

172
00:08:57,270 --> 00:08:58,119
uh

173
00:08:58,859 --> 00:08:59,760
enter

174
00:09:00,489 --> 00:09:01,400
a letter

175
00:09:03,010 --> 00:09:04,369
and then in brackets,

176
00:09:04,510 --> 00:09:06,190
I'm gonna say all

177
00:09:06,580 --> 00:09:09,030
type a Q,

178
00:09:10,520 --> 00:09:11,299
OK?

179
00:09:11,909 --> 00:09:16,099
Type Q to exit the program.

180
00:09:16,849 --> 00:09:22,349
OK? So we're giving the users here a choice. OK? You can either just type in a letter

181
00:09:22,450 --> 00:09:25,510
or if you want to exit the program, just type in Q.

182
00:09:25,830 --> 00:09:26,469
OK?

183
00:09:26,630 --> 00:09:27,150
So

184
00:09:27,880 --> 00:09:31,299
I'm going to press enter. So now let's type in

185
00:09:31,619 --> 00:09:32,940
the condition

186
00:09:33,309 --> 00:09:34,559
that most that

187
00:09:34,690 --> 00:09:38,419
we need to check whether or not the input was actually QM

188
00:09:39,020 --> 00:09:41,059
gonna come in right now, add

189
00:09:41,559 --> 00:09:43,020
the if statement.

190
00:09:43,340 --> 00:09:47,479
So we're gonna check if the user input is equal to Q,

191
00:09:47,919 --> 00:09:50,419
what should we do? Well,

192
00:09:50,859 --> 00:09:53,299
I'm going to say, print,

193
00:09:55,340 --> 00:09:56,960
uh, in brackets

194
00:09:58,969 --> 00:10:00,419
and I'm gonna say

195
00:10:01,590 --> 00:10:02,619
you have,

196
00:10:02,909 --> 00:10:03,659
you

197
00:10:04,020 --> 00:10:06,219
have chosen to exit

198
00:10:06,570 --> 00:10:07,419
the program,

199
00:10:09,090 --> 00:10:10,830
uh, just exit the program,

200
00:10:12,440 --> 00:10:13,580
press enter

201
00:10:13,890 --> 00:10:14,780
and there it is.

202
00:10:15,260 --> 00:10:18,469
And now since they've chosen to, oh, let me add the closing

203
00:10:18,799 --> 00:10:24,619
code here. Since they've chosen to exit the program, we are now going to break

204
00:10:24,900 --> 00:10:25,619
the loop.

205
00:10:27,130 --> 00:10:29,609
Otherwise I'm gonna come in here right now

206
00:10:31,880 --> 00:10:33,570
and then say print

207
00:10:37,530 --> 00:10:38,109
and thou

208
00:10:39,809 --> 00:10:40,760
in quotes

209
00:10:41,309 --> 00:10:42,179
you

210
00:10:42,900 --> 00:10:43,979
typed.

211
00:10:45,260 --> 00:10:48,320
And now remember in the curly brackets,

212
00:10:48,799 --> 00:10:52,359
I'm going to say user underscore input

213
00:10:53,210 --> 00:10:53,869
and

214
00:10:53,989 --> 00:10:55,729
there it is,

215
00:10:56,780 --> 00:10:57,159
I

216
00:10:58,440 --> 00:10:59,619
gonna go ahead right now,

217
00:10:59,719 --> 00:11:01,099
run the program.

218
00:11:02,380 --> 00:11:04,979
OK? So now it's saying enter a letter,

219
00:11:05,099 --> 00:11:06,539
I'm gonna say Y

220
00:11:06,809 --> 00:11:10,359
press enter, OK? Now it says, OK, you typed Y

221
00:11:10,559 --> 00:11:12,710
enter another letter. I'm gonna say a

222
00:11:13,520 --> 00:11:16,219
once again it's running until I now type in Q

223
00:11:16,630 --> 00:11:17,489
and now

224
00:11:17,760 --> 00:11:20,250
it has terminated the program.

225
00:11:20,650 --> 00:11:23,719
And this right here is us combining the

226
00:11:24,469 --> 00:11:25,690
our while statement,

227
00:11:25,830 --> 00:11:28,489
the wild loop brother with the break statement.

228
00:11:28,570 --> 00:11:32,809
So let me run through this over again. I know you might have a question.

229
00:11:33,090 --> 00:11:36,510
Why didn't we type in the LS?

230
00:11:36,650 --> 00:11:39,869
Because we have the if statement? OK. So where is the LS? Well,

231
00:11:40,010 --> 00:11:42,010
we could actually add the LS.

232
00:11:42,250 --> 00:11:43,609
It's going to be right here

233
00:11:44,059 --> 00:11:45,690
and I'll just say LS

234
00:11:46,369 --> 00:11:47,140
and then

235
00:11:47,380 --> 00:11:47,650
the Tate

236
00:11:48,109 --> 00:11:48,729
print,

237
00:11:49,520 --> 00:11:53,219
you typed this. So I can go ahead right now, run the exact same program again.

238
00:11:53,700 --> 00:11:55,440
OK. Come in here right now, type in G,

239
00:11:55,900 --> 00:11:56,859
it works well,

240
00:11:57,099 --> 00:12:03,469
type in U, it works well typ in Q enter and now it works the exact same way.

241
00:12:03,479 --> 00:12:06,219
So the one that you need to understand here is that

242
00:12:06,229 --> 00:12:10,830
the reason why the LS statement is actually optional here is because

243
00:12:11,140 --> 00:12:12,590
we're working with the wild

244
00:12:12,700 --> 00:12:13,179
true

245
00:12:13,619 --> 00:12:15,520
uh loop, right, the condition.

246
00:12:15,530 --> 00:12:20,960
So it's going to automatically assume that the condition will always be true.

247
00:12:21,309 --> 00:12:27,119
And now we're using the break statement here to intentionally control

248
00:12:27,330 --> 00:12:30,200
when the loop would actually end.

249
00:12:30,609 --> 00:12:34,500
So there's really no need for the else statement here.

250
00:12:34,690 --> 00:12:37,000
The loop will always run

251
00:12:37,520 --> 00:12:40,659
because we have said while true

252
00:12:40,900 --> 00:12:42,700
and will only stop

253
00:12:42,940 --> 00:12:44,979
via the break statement

254
00:12:45,130 --> 00:12:48,020
once the user has typed in the letter Q.

255
00:12:48,030 --> 00:12:51,900
So really the else statement here is not necessary,

256
00:12:51,909 --> 00:12:54,700
you can still type it in the program will still work perfectly fine.

257
00:12:54,960 --> 00:12:58,539
But whenever you're working with the while true and then the break statements,

258
00:12:58,669 --> 00:13:02,619
you don't need to add the LS condition uh any more.

259
00:13:02,929 --> 00:13:07,750
So we've done quite a lot in this particular video. Hopefully

260
00:13:07,919 --> 00:13:11,869
you've been able to follow and hopefully you now understand how the break statement

261
00:13:12,130 --> 00:13:13,489
is used.

262
00:13:13,619 --> 00:13:16,750
Thank you so much for watching the video. I will see you in the next class.