C# help declaring variable i initialize it to

Question

I'd like to declare an int variable i, initialize it to 4 and then test the following increment and decrement statements. Comment on the obtained output.

Here is the incomplete code that I made:

    class Program
    {
        static void Main(string[] args)
        {
            int Cash;
            Cash = 10;

            Console.WriteLine("{0}", ++ Cash);
            Console.WriteLine("{0}", Cash);
            Console.WriteLine("{0}", Cash ++);
        }
    }

It gives me

11, 11 11

from the output. I'm not sure If I did it correct. Can someone please correct me if I'm wrong?

You are pre-incrementing and post-incrementing. Decrementing is using `--`, if that's what you're after. — Drew Kennedy, Jun 30 '15 at 14:50
Your teacher is expecting you to understand why you get eleven three times and to be able to explain what is going on under the hood. You should read about prefix and postfix increment operators in order to rise to the challenge. — Frédéric Hamidi, Jun 30 '15 at 14:51
*"then test the following increment and decrement statements"* If that's an actual quote from the instructor, three things: 1. Your instructor should know better: They are *operators*, not *statements*. 2. There are two of each of those: The pre-increment operator (++a), post-increment operator (a++), and the equivalents for decrement (--a and a--). 3. You haven't used the decrement operators. — T.J. Crowder, Jun 30 '15 at 14:55
@T.J.Crowder About the decrement, actually the instructor included it, There are --Cash, Cash -- and Cash. But I wanted to do the rest after I see your answers. Thank a lot! For pointing out number 1 and 2. — Josh, Jun 30 '15 at 16:03

Nasreddine · Accepted Answer · 2015-06-30T14:55:10.613

2

Yes, the output is correct:

// This line increments the variable then prints its value.
Console.WriteLine("{0}", ++ Cash);
// This prints the value of the (incremented variable)
Console.WriteLine("{0}", Cash);
// The prints the value of the variable *then* increments its value
Console.WriteLine("{0}", Cash ++);

edited Jun 30 '15 at 14:55

answered Jun 30 '15 at 14:52

Nasreddine

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Thank you so much and also there's decrement operation which is Cash--, --Cash and Cash I followed the one that I made and do the rest. – Josh Jun 30 '15 at 20:16

score 1 · Answer 2 · answered Jun 30 '15 at 14:52

1

Using var++ or ++var both increment your var value. If you use var++ on a writeline, system prints the value of the var before increment it.

If you want to decrement value from a var, use var--.

answered Jun 30 '15 at 14:52

José Molero

118
10

score 1 · Answer 3 · answered Jun 30 '15 at 14:52

1

When you do ++Cash, it increments the variable first, then prints. After, you just print the variable, then on Cash++ it prints the variable before the increment. So yes your output is correct.

answered Jun 30 '15 at 14:52

Olivier Poulin

1,778
8
15

score 0 · Answer 4 · answered Jun 30 '15 at 14:51

0

++cache= update variable and then take it


cache++ = take value and than update variable

answered Jun 30 '15 at 14:51

Elisheva Wasserman

504
2
9

score 0 · Answer 5 · edited May 23 '17 at 12:29

int Cash;
Cash = 10;

Console.WriteLine("{0}", ++ Cash);
Console.WriteLine("{0}", Cash);
Console.WriteLine("{0}", Cash ++);

You initialize Cash to 10 (which should be lower case by the way). Then you preincrement before the WriteLine() is done. Thus it prints 11. The next just prints out your cash variable which is at this point 11. Then you do a post increment see link... which prints out the cash variable and then increments it. If you writeLine() your cash variable now, it will be 12.

score 0 · Answer 6 · edited May 23 '17 at 12:23

0

++ Cash is "Increase Cash by 1 and give it to me" - it will give you 11

Cash then is 11

Cash ++ is "Give me Cash and then increase it by 1" - it will give you 11 and then Cash will be 12.

Similar question: C# Pre- & Post Increment confusions

edited May 23 '17 at 12:23

Community

1
1

answered Jun 30 '15 at 14:53

keymusicman

1,281
1
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score 0 · Answer 7 · answered Jun 30 '15 at 14:53

You will find alot of valuable information on the outputs you are obtaining here:

https://msdn.microsoft.com/en-us/library/36x43w8w.aspx

Short answer is that you are doing a pre increment and post increment operation there and thus are seeing the result AFTER the operation (in this case addition of one) - the value of the variable currently, and then the result BEFORE the operation. This is why you see 11 all three times.

cheers.

C# help declaring variable i initialize it to

7 Answers7