1
00:00:00,510 --> 00:00:02,960
Hello and welcome to this video.

2
00:00:03,000 --> 00:00:10,950
In this video I'm going to introduce you to another conditional type of statement called the TELL IF

3
00:00:11,220 --> 00:00:20,580
statement the L if statement is calm like a bridge or a combination of one else statement and an if

4
00:00:20,970 --> 00:00:29,850
statement was kind of like to type of statements combined to one the L if statements are basically used

5
00:00:29,850 --> 00:00:39,840
to check for multiple expressions that are true in your program so they check for several conditions

6
00:00:39,840 --> 00:00:48,990
that are true and if one of them is true it execute the first one it finds and then ignores the rest.

7
00:00:48,990 --> 00:00:55,470
So when you have an if statement if statement would check if a condition is true and then execute the

8
00:00:55,470 --> 00:01:02,890
block of code inside that if block and if the condition is not true it doesn't do anything.

9
00:01:03,120 --> 00:01:10,110
A eal or L if statement is kind of like multiple if statements.

10
00:01:10,260 --> 00:01:16,800
So it gives you options to check for conditions that are true.

11
00:01:17,160 --> 00:01:25,530
They will only execute a block of code as soon as one of the conditions evaluates to true.

12
00:01:25,530 --> 00:01:30,350
It will only execute that block and it will ignore the other code.

13
00:01:31,200 --> 00:01:37,350
So this is what a typical syntax looks like for an L if statement.

14
00:01:37,370 --> 00:01:44,790
So you start with the if statement which will count as the first condition to check if is true and if

15
00:01:44,790 --> 00:01:50,140
it's true you execute the block of code that is indented for that.

16
00:01:50,190 --> 00:01:57,500
If block if that condition is not met it goes onto the l.

17
00:01:57,510 --> 00:02:01,530
If block and checks for the second condition that is true.

18
00:02:01,530 --> 00:02:10,230
If that condition is true it will execute the block of code on the L if condition is very important

19
00:02:10,230 --> 00:02:15,990
to take note of the colon colon tells Python to execute a block of code.

20
00:02:15,990 --> 00:02:22,770
It also tells Python that you are starting a new line of code and the code must be indented indentation

21
00:02:22,770 --> 00:02:28,850
is important so that you know what could block belongs to setting condition.

22
00:02:28,950 --> 00:02:34,930
So let me show you an example of how the L if statement can work.

23
00:02:35,280 --> 00:02:37,100
So I've already got a python file.

24
00:02:37,110 --> 00:02:45,850
I'm just going to create two variables I create variable a and I'll give it a value of seven.

25
00:02:45,870 --> 00:02:53,020
Now create another variable B and I'll give it a value of 8.

26
00:02:53,030 --> 00:03:06,920
Now I can start with my if block so say if the value a is greater than the value B then I'll do my colon

27
00:03:07,610 --> 00:03:12,370
to tell Python that I want to start a new line of code.

28
00:03:12,460 --> 00:03:19,070
Presenter You can see automatically indents it for me so I'm gonna type in a print statement.

29
00:03:19,070 --> 00:03:26,180
I will say print and inside the parentheses of that print function.

30
00:03:26,190 --> 00:03:29,850
I'm going to specify the code that will execute.

31
00:03:30,050 --> 00:03:37,400
So I'm going to say ay ay I'm referring to the value of the variable a no say you can type in anything

32
00:03:37,400 --> 00:03:37,850
you want.

33
00:03:37,850 --> 00:03:41,020
Doesn't really matter is smaller.

34
00:03:41,860 --> 00:03:50,450
And then our exit the string with a comma it's important you add your comma so that the interpreter

35
00:03:50,450 --> 00:03:55,720
knows the difference between a normal variable and a normal string.

36
00:03:55,720 --> 00:03:56,180
All right.

37
00:03:56,180 --> 00:04:04,940
So now this is my if block so you can see by indentation you can tell that this block of code belongs

38
00:04:04,940 --> 00:04:06,690
to this if block.

39
00:04:06,800 --> 00:04:11,180
So now I want to add an else block.

40
00:04:11,390 --> 00:04:17,230
You can add as many L if block if you want.

41
00:04:17,250 --> 00:04:19,700
So you don't necessarily have to have just one.

42
00:04:19,700 --> 00:04:28,280
If you want to have several conditions to test for true you can add as many as you want something else.

43
00:04:28,280 --> 00:04:35,080
If I'm checking on other condition e.g. variable b let me reverse that.

44
00:04:35,080 --> 00:04:47,530
I'll say if the variable B which is eight years is greater than the variable a two column then I want

45
00:04:47,650 --> 00:04:50,730
certain block of code to execute.

46
00:04:51,040 --> 00:05:00,550
So inside onto a print statement and inside that print statement I will specify what I want done.

47
00:05:00,630 --> 00:05:05,570
Let's keep the string and do a comma and say a.

48
00:05:05,670 --> 00:05:15,070
So this is my else if block you can have as many as you want depending on how many conditions you want

49
00:05:15,070 --> 00:05:17,260
to test for that are true.

50
00:05:17,430 --> 00:05:27,880
The code will check the Port St. side beef block first that is a block that will run first is checking

51
00:05:28,080 --> 00:05:30,370
is the value of a which is seven.

52
00:05:30,370 --> 00:05:33,640
Is it greater than B.

53
00:05:33,820 --> 00:05:35,020
It is not.

54
00:05:35,020 --> 00:05:36,460
So that's condition.

55
00:05:36,460 --> 00:05:38,870
This condition is false.

56
00:05:38,880 --> 00:05:41,620
That means this code here will not run.

57
00:05:41,620 --> 00:05:47,810
So it jumps to this other condition the L if block and checks the condition.

58
00:05:47,860 --> 00:05:51,890
Notice I'm using the operators to check.

59
00:05:51,910 --> 00:05:53,260
This is the greater than sign.

60
00:05:53,290 --> 00:05:54,450
This is a greater than.

61
00:05:54,460 --> 00:06:01,660
There are many other operators comparison operators and logical operators you can use a value.

62
00:06:01,660 --> 00:06:05,250
Just use the greater down just for simplicity.

63
00:06:05,350 --> 00:06:10,870
Depending on what condition you are testing you use the appropriate operator.

64
00:06:10,930 --> 00:06:14,000
So this block in the IFF is wrong.

65
00:06:14,020 --> 00:06:16,320
That is it has not tested true.

66
00:06:16,330 --> 00:06:26,020
So that code will not run the code in the L. if is true because B is greater than a B's 8 which is greater

67
00:06:26,020 --> 00:06:27,030
than 7.

68
00:06:27,040 --> 00:06:33,960
So what will happen this block of code will execute c if I press play.

69
00:06:34,200 --> 00:06:42,110
You can see here this code here what I say B is bigger than a B is 8.

70
00:06:42,110 --> 00:06:49,980
It says 8 is bigger than 7 so you can see that block of code executes both the first one does not execute

71
00:06:50,380 --> 00:06:53,420
so you can see the importance of the L.

72
00:06:53,440 --> 00:07:00,300
If so you can add as many L if in your code as required.

73
00:07:00,310 --> 00:07:09,360
I've only just used 2 1 just for simplicity so that's it for this video on the L if conditional statement.

74
00:07:09,370 --> 00:07:10,630
Thank you for watching.

75
00:07:10,630 --> 00:07:11,720
Bye for now.