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need code to check if the value is numeric in C

Mikerush74-Oct-12 6:49

4-Oct-12 6:49

I am student, taking C programming now.
I have assignment to write function to check if inputed data is numbers. if not - it should write that, and ask to enter number again.
I wrote code, to write error message, but dont know how to make program to work on next input.. should I call the Main function again ?

int main()
{

double hours; //hours worked in a week
double payrate; // hourly salary
double grosspay; //total weekly payment
int k; //number of values read

printf ("Enter number of hours, and hourly pay (or press 0 to exit) \n");

while ((k = scanf ("%lf%lf", &hours, &payrate))==2)
{

if (isdigit(hours) !=0)
return hours;
else
printf ("You entered invalid data, please enter number of hours \n");

if (isdigit(payrate) !=0)
return payrate;
else
printf ("You entered invalid data, please enter payrate \n");

if (hours==0 || payrate==0)
{
printf ("Good Bye. \n\n");
system("PAUSE");
return 0;
}

double grosspay;
grosspay = calculateGrossPay(hours, payrate);

printf ("Hours worked: %.2f\n", hours);
printf ("Hourly Rate: %.2f\n\n", payrate);
printf ("Your weekly payment is: $ %.2f \n\n\n", grosspay);

Re: need code to check if the value is numeric in C

Richard MacCutchan4-Oct-12 7:22

Richard MacCutchan

4-Oct-12 7:22

You cannot use a double parameter as input to the isdigit()[^] function. You should read your numbers in as strings and then apply isdigit() to each character, using a loop. Rather than having all your code in the main() function, you may want to think about writing a helper function that will input the string, validate it and return the converted value.

One of these days I'm going to think of a really clever signature.

Re: need code to check if the value is numeric in C

Mikerush74-Oct-12 7:50

Mikerush7

4-Oct-12 7:50

i dont really know how to do that yet... Ok, i will try..
is there a general format of that function somewhere?

Re: need code to check if the value is numeric in C

Richard MacCutchan4-Oct-12 7:53

Richard MacCutchan

4-Oct-12 7:53

Mikerush7 wrote:
is there a general format of that function somewhere?

Assuming you mean isdigit(), I put the link in my previous message.

One of these days I'm going to think of a really clever signature.

Re: need code to check if the value is numeric in C

CPallini4-Oct-12 9:48

CPallini

4-Oct-12 9:48

Mikerush7 wrote:
while ((k = scanf ("%lf%lf", &hours, &payrate))==2)

If scanf succeeds then you need no other check.

Mikerush7 wrote:
should I call the Main function again

No. You may call scanf (if you are allowed to use it) many times inside your main function.

Veni, vidi, vici.

Re: need code to check if the value is numeric in C

David Crow4-Oct-12 9:55

David Crow

4-Oct-12 9:55

Mikerush7 wrote:

while ((k = scanf ("%lf%lf", &hours, &payrate))==2)

Without a full understanding of assignments and expressions, mixing the two in one statement is highly discouraged.

Mikerush7 wrote:

return hours;

While I'm not sure who you'd be returning hours worked to or why, the compiler should have at least warned you about loss of data.

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"Show me a community that obeys the Ten Commandments and I'll show you a less crowded prison system." - Anonymous

Re: need code to check if the value is numeric in C

Richard MacCutchan4-Oct-12 21:37

Richard MacCutchan

4-Oct-12 21:37

DavidCrow wrote:
the compiler should have at least warned you

Given the number of syntax errors elsewhere I don't think a compiler has ever seen this sample.

One of these days I'm going to think of a really clever signature.

Re: need code to check if the value is numeric in C

Mikerush75-Oct-12 8:30

Mikerush7

5-Oct-12 8:30

thank you everybody for help. I will keep working on it. my teacher is not helping, so I am on my own..

Re: need code to check if the value is numeric in C

C Mahesh8-Oct-12 22:24

C Mahesh

8-Oct-12 22:24

Build your logic based on the following example.

int main( )
{
char n ;
int no = 0 ;
printf("Enter a no " );
while( (n = (char)getche( )) != '\r') //Check for enter key
{
if( n >= '0' && n <= '9' )
{
n = n - 48 ;
no = (no * 10) + n ;
}
else{
printf("\nInvalid. ");
}
}
printf("\n %d " , no ) ;
return 0 ;
}

i want any code to make project

emanalshboul3-Oct-12 12:54

emanalshboul

3-Oct-12 12:54

i,m astuedent in university ,and my doctor want from every
student aproject ,and i want code to make from that (requirement,design,and testing)
please send me code by c++ language such as about
how identification digit system works
and welcome

eman

Re: i want any code to make project

Peter_in_27803-Oct-12 13:48

Peter_in_2780

3-Oct-12 13:48

I think what your teacher wants is for you to develop the project yourself.

Pick a topic.
Read up on it. (Google is a good place to start.)
Get working on it.
If you have some specific problem with some detail, come back here and ask a question.
We are not in the business of writing your project for you.

Peter

Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012

Re: i want any code to make project

Mohibur Rashid3-Oct-12 18:55

Mohibur Rashid

3-Oct-12 18:55

Ok eman, You ask this question twice. You cant have a project asking online. No one will help you, no one will even suggest you a project.

Help yourself.

I wish I could believe there is an after life.

Re: i want any code to make project

David Crow4-Oct-12 2:51

David Crow

4-Oct-12 2:51

emanalshboul wrote:
...my doctor want from every student...

emanalshboul wrote:
...please send me code...

What do you think your "doctor" would say if you turned in someone else's code? Roll eyes | :rolleyes:

Re: i want any code to make project

Richard MacCutchan4-Oct-12 4:30

Richard MacCutchan

4-Oct-12 4:30

DavidCrow wrote:
What do you think your "doctor" would say

"Young man, you are suffering from a virus". Wink | ;)

One of these days I'm going to think of a really clever signature.

static text boxes and using the wizard to initialize a variable

AndrewG12313-Oct-12 11:46

AndrewG1231

3-Oct-12 11:46

When I am designing a dialog box with static text boxes to display numbers can I initialize control variables as arrays through the wizard?

As an example, say I am collecting information in 8 channels and would like to display this information in a 8 separate text boxes. I want to store the information in the variable int m_chan[8] but I don't see the array option in the 'Add Variable...' in VS2010.

Re: static text boxes and using the wizard to initialize a variable

Mohibur Rashid3-Oct-12 18:51

Mohibur Rashid

3-Oct-12 18:51

The answer is "No you cannot". But you can apply various method to achieve that simpley

You can remind in your two variable your first id and last id, if they are incremental. on various occasion we have to create more than one static object, dynamically.

I wish I could believe there is an after life.

Re: static text boxes and using the wizard to initialize a variable

«_Superman_»3-Oct-12 19:04

«_Superman_»

3-Oct-12 19:04

The Add Variable wizard does not support what you want to do.
However, you can add the variables manually to get at what you're trying to do.

For the first text box, right click and select Add Variable.
Then select the datatype as int and enter the name of the variable as m_chan.

After this, open the dialog header file and change the member variable from int m_chan; to int m_chan[8];.

Now open the dialog source file and make the following changes -

At the dialog constructor remove the line , m_chan(0).

In the DoDataExchange function, remove the line DDX_Text(pDX, IDC_EDIT1, m_chan); and add the following lines -

DDX_Text(pDX, IDC_EDIT1, m_chan[0]);
DDX_Text(pDX, IDC_EDIT2, m_chan[1]);
DDX_Text(pDX, IDC_EDIT3, m_chan[2]);
DDX_Text(pDX, IDC_EDIT4, m_chan[3]);
DDX_Text(pDX, IDC_EDIT5, m_chan[4]);
DDX_Text(pDX, IDC_EDIT6, m_chan[5]);
DDX_Text(pDX, IDC_EDIT7, m_chan[6]);
DDX_Text(pDX, IDC_EDIT8, m_chan[7]);

Here, replace the IDs of the edit boxes to the appropriate IDs.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Polymorphism in C

Re: static text boxes and using the wizard to initialize a variable

Marius Bancila4-Oct-12 0:41

Marius Bancila

4-Oct-12 0:41

The wizard is limited; you should get used to skip the wizard. Many times it's even faster to add something to your code, than using the wizard. What you want is possible (as shown already), but not with the wizard.

need help with client server

aajibade3-Oct-12 6:45

aajibade

3-Oct-12 6:45

how do i go abt starting creating a client and server program will really appreciate a the help than

Re: need help with client server

David Crow3-Oct-12 6:53

David Crow

3-Oct-12 6:53

Start here.

How to create C++/CLI Interface to access .net API from C++ code?

litu kumar3-Oct-12 2:14

litu kumar

3-Oct-12 2:14

Hi,

I have created a win32 dll(VC++). And I know the appropriate .net assembly file which contains the required methods.
I want to access those methods from my DLL.

I came to know , it can possible through C++/CLI interface.
But i'm very new to C++/CLI . So kindly help me to create such interface in C++ which can access those methods using certain assembly/any way.

If have any any sample example (running),then please share me soon. I tried a lot in google , but till now i didn't get any helpful samples .

Thanks in advance Smile Smile | :)

Crosspost

Peter_in_27803-Oct-12 2:24

Peter_in_2780

3-Oct-12 2:24

Please ask your question ONCE. Crossposting like this will only annoy the people who might otherwise halp you.

Peter

Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012

Re: Crosspost

litu kumar3-Oct-12 2:30

litu kumar

3-Oct-12 2:30

Thanks peter for the information.

Actually i got a suggestion to post in VC++ section while i posted it 1st time.

Thats the reason i posted once again here.

Any thing you would like to suggest, then please...

Thanks

Re: Crosspost

Richard MacCutchan3-Oct-12 2:32

Richard MacCutchan

3-Oct-12 2:32

I cannot find any response telling you to post it here. This is an obvious C++/CLI question and does not belong in this forum.

One of these days I'm going to think of a really clever signature.

Re: Crosspost

Peter_in_27803-Oct-12 2:48

Peter_in_2780

3-Oct-12 2:48

Beat me to it. Thanks.

Peter

Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012

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