1
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Using the comma operator.

2
00:00:02,500 --> 00:00:05,440
The operator shall be covered later in the section.

3
00:00:06,010 --> 00:00:10,630
However, it's useful to introduce the comma operator here.

4
00:00:11,650 --> 00:00:17,160
So you can have a second set of expression separated by a comma as a single statement.

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00:00:17,170 --> 00:00:23,210
For example, let's create an example code here to show you how this common trait works.

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Integer A equals nine.

7
00:00:25,510 --> 00:00:27,820
For example, integer equals nine.

8
00:00:28,300 --> 00:00:29,240
Integer.

9
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B equals four.

10
00:00:33,780 --> 00:00:34,340
Integers.

11
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C equals nothing.

12
00:00:36,360 --> 00:00:39,360
So it's you automatically zero.

13
00:00:40,140 --> 00:00:50,850
So let's see, equals E plus eight and com operator B plus one.

14
00:00:51,630 --> 00:00:55,650
So as you can see here, we have a slight problem here.

15
00:00:55,680 --> 00:01:03,870
So this code compiled and run with that problem and the variable C will be assigned with the value of

16
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17.

17
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Let's print it and I will show you what this is.

18
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See here.

19
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And std.

20
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STD and L here.

21
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So let's apprentice here.

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As you can see here, we got 11.

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So a plus nine, a plus nine and we will get 11.

24
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But where is our five?

25
00:01:33,680 --> 00:01:38,150
So as you know, four plus one equals.

26
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Equals five.

27
00:01:41,040 --> 00:01:42,800
So here.

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SAMILTON.

29
00:01:44,600 --> 00:01:45,290
And.

30
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Uh, 17 and five.

31
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As you can see, this 17 and five did not multiply.

32
00:01:54,530 --> 00:01:56,270
So that's because of the.

33
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The commerce operator is not a multiply here.

34
00:01:59,420 --> 00:02:01,790
So I will explain what this comma is.

35
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So the reason is that this is the reason that the comma operator.

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Separates the right side of the assignment into two expressions.

37
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A plus one and B plus A plus eight and B plus one.

38
00:02:21,800 --> 00:02:27,170
And it uses the value of the first expression to assign C.

39
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Later in this course, we will look at the operator precedence.

40
00:02:32,780 --> 00:02:43,370
However, it's worth saying here that the comma has the lowest precedence and plus has higher precedence

41
00:02:44,900 --> 00:02:47,350
than equal to sign here.

42
00:02:47,390 --> 00:02:54,650
So the statement is executed in order of the addition to the addition of the addition.

43
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So the assignment and then the comma operator with the result of B plus one thrown away just as earlier.

44
00:03:02,630 --> 00:03:11,660
As you can see, we just get 17 from C here so you can change the presidents using the parentheses to

45
00:03:11,660 --> 00:03:12,650
group expressions.

46
00:03:12,650 --> 00:03:15,340
For example, let's.

47
00:03:17,180 --> 00:03:21,670
And mistyped called could have been here as follows.

48
00:03:21,680 --> 00:03:26,620
Let's get into the parenthesis and see what happens here.

49
00:03:26,630 --> 00:03:29,840
As you can see here, we got the five now.

50
00:03:30,970 --> 00:03:40,170
So the result of this statement is variable C assigned to five, B plus one, and where is our 17 here?

51
00:03:40,180 --> 00:03:46,230
So the reason is that with the common operator expression are executed from the left to right.

52
00:03:46,240 --> 00:03:50,770
So the value of the group of expression is the most one.

53
00:03:50,770 --> 00:03:57,220
So there are some cases, for example in the initialization or loop expression for a for loop where

54
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you will find the common operator useful.

55
00:04:00,130 --> 00:04:08,650
But as you can see here, even used intentionally, the common operator produced hard to read code.

56
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So now actually.

57
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Let's end our.

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Lecture now, and in the next lecture you will learn about your types and variables.