Why doesn't this code call the next method?

Question

1.00/5 (1 vote)

See more:

I can't figure out why the Main method won't call the GetData method.Can someone point me in the right direction? Thanks

C#

// GetData() method accepts order number and quantity
// that are used in the Main() method
// Price is $3.99 each
using System;
class DebugEight1
{
    static void Main()
    {
        
        int orderNum = 0, quantity = 0;
        double total;
        const double PRICE_EACH = 3.99;
        GetData(  out orderNum, out quantity);

        total = quantity * PRICE_EACH;

        Console.WriteLine(" Order #(), Quantity ordered ()",
            orderNum, quantity);
        Console.WriteLine("Total is {0}", total.ToString("C"));
       
    }
    private static void GetData( out int orderNum, out int quantity)
    {
        
        String s1, s2;
        Console.Write("Enter order number ");
        s1 = Console.ReadLine();
        Console.Write("Enter quantity ");
        s2 = Console.ReadLine();
        orderNum = Convert.ToInt32(s1);
        quantity = Convert.ToInt32(s2);
    }
}

Posted 5-Mar-15 6:25am

Member 11403574

Updated 5-Mar-15 8:14am

v2

Add a Solution

Comments

Richard MacCutchan 5-Mar-15 13:08pm

If it does not compile (which I suspect) then please show us the error messages and the lines on which they occur.

Member 11403574 5-Mar-15 13:11pm

Actually there are no errors. It opens the window and then it simply says "press any key to continue" and then closes when you press enter or any other key. So I guess it is compiling just not correctly.

Sergey Alexandrovich Kryukov 5-Mar-15 13:26pm

Apparently, it does call it. Use the debugger. Are you sure this is the application assembly? Are you sure it even compiles?
—SA

Member 11403574 5-Mar-15 13:27pm

I do use the debugger. And it opens the window and then it simply says "press any key to continue" and then closes when you press enter or any other key.

4 solutions

Solution 2

The problem is that this code doesn't compile.
In C# you must initialize variables before you can use them unless you use them as out parameters.
Trying to figure out your intention writing this code, I think what you are really trying to do is to call the GetData() method and pass the parameters by reference.

In order to make it work you have two choices:
1. Initialize the variables orderNum and quantity and put the keyword "ref" before them in the call to the GetData() method and inside the GetData() method declaration like this:

C#

int orderNum = 0, quantity = 0;
GetData(ref orderNum, ref quantity);

private static void GetData(ref int orderNum, ref int quantity)
{
....
....
}

2. Just put the keyword "out" before the orderNum and quantity variables before calling the GetData() method like this:

GetData(out orderNum, out quantity);

And change the method declaration of GetData() to this:

C#

private static void GetData(out int orderNum, out int quantity)
{
....
....
}

Good luck!
Dudi Avrahamov
Software Consultant
il.linkedin.com/in/dgsoft

Posted 5-Mar-15 6:54am

Dudi Avrahamov

Updated 5-Mar-15 7:37am

v2

Comments

Member 11403574 5-Mar-15 13:01pm

I have tried both methods you suggested and strangely enough, it still doesn't compile. I'm puzzled.

Solution 5

You need to change your code as follows:

C#

static void Main()
{
	int orderNum, quantity;
	double total;
	const double PRICE_EACH = 3.99;
// GetData needs the 'out' attribute on the two varuiables
	GetData(out orderNum, out quantity);
	total = quantity * PRICE_EACH;
// the display line needs identifiers '{x}' for the parameters
	Console.WriteLine(" Order #({0}), Quantity ordered = ({1})",
		orderNum, quantity);
	Console.WriteLine("Total is {0}", total.ToString("C"));

}
// use 'out' as above
private static void GetData(out int orderNum, out int quantity)
{
	String s1, s2;
	Console.Write("Enter order number ");
	s1 = Console.ReadLine();
	Console.Write("Enter quantity ");
	s2 = Console.ReadLine();
	orderNum = Convert.ToInt32(s1);
	quantity = Convert.ToInt32(s2);
}

Posted 5-Mar-15 8:01am

Richard MacCutchan

Comments

Member 11403574 5-Mar-15 14:08pm

Yes sir, I did do that but it still doesn't work. I would re post my code so you can see what I have now but I don't know if that's allowed here

Richard MacCutchan 6-Mar-15 2:54am

I don't know what you did but I can assure you that the above code works. You can go to your original post above, click on Improve question and edit the content to show the exact code you have now. And if you have any compile errors then please show them also.

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Accepted Answer · 2015-03-05T06:35:00

Well it should do - unless you have another method called Main, that isn't in that class?
So start by checking if it executes that Main method: put a breakpoint on the first line, and run your app in the debugger. If it hits the breakpoint, your app will stop and wait for you. Step though until you do (or don't) get into the GetData method.

As Dudi suggested, it doesn't compile, because of the parameter problems.
You can fix that, it's not complex:

C#

static void Main()
    {

    int orderNum, quantity;
    double total;
    const double PRICE_EACH = 3.99;
    GetData(out orderNum, out quantity);
    total = quantity * PRICE_EACH;
    Console.WriteLine(" Order #{0}, Quantity ordered = {0}",
        orderNum, quantity);
    Console.WriteLine("Total is {0}", total.ToString("C"));

    }
private static void GetData(out int orderNum, out int quantity)
    {
    String s1, s2;
    Console.Write("Enter order number ");
    s1 = Console.ReadLine();
    Console.Write("Enter quantity ");
    s2 = Console.ReadLine();
    orderNum = Convert.ToInt32(s1);
    quantity = Convert.ToInt32(s2);
    }

But the code that results, is a bit...um...poor.
Instead, try doing this:

C#

const double PRICE_EACH = 3.99;
static void Main()
    {
    int orderNum = GetValue("Enter Order number : ");
    int quantity = GetValue("Enter Quantity     : ");
    double total = quantity * PRICE_EACH;
    Console.WriteLine("Order #{0}, Quantity ordered = {0}", orderNum, quantity);
    Console.WriteLine("Total is {0}", total.ToString("C"));
    }

private static int GetValue(string prompt)
    {
    int value;
    do
        {
        Console.Write(prompt);
        } while (!int.TryParse(Console.ReadLine(), out value));
    return value;
    }

This doesn't crash if the user enters a "bad" value - it prompts him and gets it again.
It also uses a method in a more "normal" way - to return the value you are interested in.

Try it. See what happens.

HKHerron · Accepted Answer · 2015-03-05T07:34:00

Solution 4

C#

// GetData() method accepts order number and quantity
// that are used in the Main() method
// Price is $3.99 each
using System;
class DebugEight1
{
    static void Main()
    {
        
        int orderNum = 0, quantity = 0;
        double total;
        const double PRICE_EACH = 3.99;
        GetData(  out orderNum, out quantity);
 
        total = quantity * PRICE_EACH;
 
        Console.WriteLine(" Order #(), Quantity ordered ()",
            orderNum, quantity);
        Console.WriteLine("Total is {0}", total.ToString("C"));
       
    }
    private static void GetData( out int orderNum, out int quantity)
    {
        
        String s1, s2;
        Console.Write("Enter order number ");
        s1 = Console.ReadLine();
        Console.Write("Enter quantity ");
        s2 = Console.ReadLine();
        orderNum = Convert.ToInt32(s1);
        quantity = Convert.ToInt32(s2);
    }
}

Posted 5-Mar-15 7:34am

HKHerron

Updated 5-Mar-15 10:16am

v2

Comments

Member 11403574 5-Mar-15 13:42pm

I appreciate your help, but I don't want to use your code, I would rather discover why mine doesn't work.

HKHerron 5-Mar-15 13:48pm

This is your code. All I did was fix it!

phil.o 5-Mar-15 22:49pm

Then an explanation of what you fixed and why is more useful than just posting some code without any explanation.

Member 11403574 5-Mar-15 13:51pm

Thank You

HKHerron 5-Mar-15 13:53pm

OK, for starters, your code wont work because your GetData method does not return any information back to the Main method. Unless declared properly, variable declared in methods are not accessible to other methods. By using a class, you can pass this information between methods!

Member 11403574 5-Mar-15 13:59pm

Is there another way to pass the data without creating a class? Just curious

HKHerron 5-Mar-15 14:01pm

Your code creates an error in the line: GetData(orderNum, quantity);
"Use of unassigned local variable" - This is what we were asking for!

This is because your variables: orderNum and quantity are null!

Change this line: int orderNum, quantity;

to this: int orderNum=0, quantity=0;

Philippe Mori 8-Oct-15 12:59pm

This is totally useless. You don't have to initialize out parameters.

Member 11403574 5-Mar-15 14:04pm

Oh, I did do that. It still doesn't work. Will I get in trouble if I post my code again so you can see what I have now?

HKHerron 5-Mar-15 14:10pm

That's because your code still doesn't return any data beck to main. Look at solution 5, or Yes, you can do it like this, but it changes your classes to public!

using System;

public class DebugEight1
{
public static int orderNum = 0;
public static int quantity = 0;

public static void Main()
{
double total;
const double PRICE_EACH = 3.99;
DebugEight1.GetData();
total = quantity * PRICE_EACH;
Console.WriteLine(" Order #{0}, Quantity ordered = {1}", orderNum, quantity);
Console.WriteLine("Total is {0}", total.ToString("C"));
Console.WriteLine("=================================");
Console.WriteLine("Hit key to quit:");
Console.ReadKey();
}

public static void GetData()
{
String s1, s2;
Console.Write("Enter order number ");
s1 = Console.ReadLine();
Console.Write("Enter quantity ");
s2 = Console.ReadLine();
orderNum = Convert.ToInt32(s1);
quantity = Convert.ToInt32(s2);
}

Post your new code in a comment, or you can update your first post!

Member 11403574 5-Mar-15 14:46pm

I updated my original code, would you please take a look at it?

Member 11403574 5-Mar-15 14:15pm

I updated my original code, would you please take a look at it?

HKHerron 5-Mar-15 14:47pm

It works for me!

You need to change this line:

Console.WriteLine(" Order #(), Quantity ordered ()",orderNum, quantity);

to this:

Console.WriteLine(" Order #{0}, Quantity ordered {1}",orderNum, quantity);

Member 11403574 5-Mar-15 14:53pm

Now it works, Thank you so much, you have no idea what this was doing to my brain!

HKHerron 5-Mar-15 14:55pm

Great, you should select it as your Solution!

Member 11403574 5-Mar-15 15:00pm

I did :) Thanks

HKHerron 5-Mar-15 15:03pm

No, not mine, you used your code!

Member 11403574 5-Mar-15 15:05pm

But my code didn't work without your added suggestions

HKHerron 5-Mar-15 15:26pm

Actually, it was more @OriginalGriff code.

Why doesn't this code call the next method?

4 solutions

Solution 1

Solution 4

Solution 2

Solution 5

Add your solution here

Preview 0

Existing Members

...or Join us