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Pls help me with this Struct function

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Join Date: May 2008

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J-son

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Pls help me with this Struct function

Sep 11th, 2008

Hi there ... I need help with the following program.It is giving me error. Thanks very much.

 Help with Code Tags 
 c Syntax (Toggle Plain Text) 
/*Write a structure function to enter Roll number, Name, Department, Course, Year of joining and print them out */
 
#include <stdio.h>
struct student
{
	char name;
	char dep;
	char course;
	int roll;
	int year;
};
main( )
{
	struct student d1[5];
	name(d1) ;
}
 
name(struct student d2[5])
{
	int i;
	printf("Enter Roll Number,Name, Department, Course, Year of Joining\n");
 
	for(i=0;i<=2;i++){
	fflush(stdin);
	scanf("%d %s %s %s %d",&d2[i].roll,&d2[i].name,&d2[i].dep,&d2[i].course,&d2[i].year);
	}
	for(i=0;i<=2;i++)
	printf("\nRoll Number:%d Name:%s Department:%s Course:%s Year of Joining:%d",d2[i].roll,d2[i].name,d2[i].dep,d2[i].course,d2[i].year);
}
/*Write a structure function to enter Roll number, Name, Department, Course, Year of joining and print them out */

#include <stdio.h>
struct student
{
	char name;
	char dep;
	char course;
	int roll;
	int year;
};
main( )
{
	struct student d1[5];
	name(d1) ;
}

name(struct student d2[5])
{
	int i;
	printf("Enter Roll Number,Name, Department, Course, Year of Joining\n");
	
	for(i=0;i<=2;i++){
	fflush(stdin);
	scanf("%d %s %s %s %d",&d2[i].roll,&d2[i].name,&d2[i].dep,&d2[i].course,&d2[i].year);
	}
	for(i=0;i<=2;i++)
	printf("\nRoll Number:%d Name:%s Department:%s Course:%s Year of Joining:%d",d2[i].roll,d2[i].name,d2[i].dep,d2[i].course,d2[i].year);
}

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Join Date: Oct 2006

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niek_e

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Cenosillicaphobiac

Re: Pls help me with this Struct function

Sep 11th, 2008

A few things:

it's int main() , and you have to return 0;
The other thing is, that you didn't tell the compiler what the function "name" should return. I'll asume it's void?
The last thing is that you didn't define the function "name" before you use it. So you'll have to move the function above main().

Also read this about using scanf and this about fflush

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Join Date: Jul 2008

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ArkM

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Re: Pls help me with this Struct function

Sep 11th, 2008

Some additions:
1. If no returned type explicitly defined in C and C++, int assumed (backward compatibility with Stone Age of the C language). Of course, now it's bad style.
2. Effect of input stream fflush is not defined in the C language.
3. Declare name and dep members as arrays of char! Now you crash your program with attempt to input strings into single chars!
4. Use code structured indentation!
5. Never ask user to type a line without prompting.

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Join Date: May 2008

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J-son

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Newbie Poster

Re: Pls help me with this Struct function

Sep 11th, 2008

Thanks very much for ur helps but sorry ... I don't get what u mean. I m just a beginner. Here I removed function and tested, it run, compiled but error with result.
What should I do? Thanks anyway.

 Help with Code Tags 
 c Syntax (Toggle Plain Text) 
#include <stdio.h>
int main( )
{
	struct student
		{
			char name;
			char dep;
			char course;
			int roll;
			int year;
		};
	struct student d2[3];
	int i;
	printf("Enter Roll Number,Name, Department, Course, Year of Joining\n");
	for (i=0;i<=2;i++){
			scanf("%d %c %c %c %d",&d2[i].roll,&d2[i].name,&d2[i].dep,&d2[i].course,&d2[i].year);
		}
	for (i=0;i<=2;i++)
		printf("\nRoll Number:%d Name:%c Department:%c Course:%c Year of Joining:%d",d2[i].roll,d2[i].name,d2[i].dep,d2[i].course,d2[i].year);
	return 0;
}
#include <stdio.h>
int main( )
{
	struct student
		{
			char name;
			char dep;
			char course;
			int roll;
			int year;
		};
	struct student d2[3];
	int i;
	printf("Enter Roll Number,Name, Department, Course, Year of Joining\n");
	for (i=0;i<=2;i++){
			scanf("%d %c %c %c %d",&d2[i].roll,&d2[i].name,&d2[i].dep,&d2[i].course,&d2[i].year);
		}
	for (i=0;i<=2;i++)
		printf("\nRoll Number:%d Name:%c Department:%c Course:%c Year of Joining:%d",d2[i].roll,d2[i].name,d2[i].dep,d2[i].course,d2[i].year);
	return 0;
}

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Join Date: Jul 2008

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ahamed101

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Junior Poster

Re: Pls help me with this Struct function

-1

Sep 28th, 2008

Hi there,

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
	for (i=0;i<=2;i++){
		fflush(stdin);
			scanf("%d %c %c %c %d",&d2[i].roll,&d2[i].name,&d2[i].dep,&d2[i].course,&d2[i].year);
		}
	for (i=0;i<=2;i++){
		fflush(stdin);
			scanf("%d %c %c %c %d",&d2[i].roll,&d2[i].name,&d2[i].dep,&d2[i].course,&d2[i].year);
		}

Just add fflush(stdin) inside the for loop... this will solve your problem...
To remember : Always use fflush(stdin) before scanf() cause if not done, the input which you have given will remain in the input stream and it will get read by scanf next time...

regards,
Ahamed.

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ArkM

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Postaholic

Re: Pls help me with this Struct function

Sep 28th, 2008

Never add fflush(stdin) - fflush() works with output or update streams only. See, for example:
http://www.opengroup.org/onlinepubs/...ns/fflush.html

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Join Date: Jul 2008

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ahamed101

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Junior Poster

Re: Pls help me with this Struct function

Sep 28th, 2008

Hi ArkM,
How else can we clear the input stream?... I think the issue with the above code is basically the input stream is not cleared... I also read that the usage of fflush for stdin is undefined...

Regards,
Ahamed

regards,
Ahamed.

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Join Date: Sep 2008

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Sci@phy

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Posting Whiz in Training

Re: Pls help me with this Struct function

Sep 28th, 2008

fflush should not work with input stream!
But in some compilers it does!
That's all

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ssharish2005 ssharish2005 is offline

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Re: Pls help me with this Struct function

Sep 28th, 2008

•

Originally Posted by ahamed101

Hi ArkM,
How else can we clear the input stream?... I think the issue with the above code is basically the input stream is not cleared... I also read that the usage of fflush for stdin is undefined...

Regards,
Ahamed

Use this instead

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
void clrInputBuf( void )
{
     int ch;
 
     while( ( ch = getchar() ) != '\n' && ch != EOF );
}
void clrInputBuf( void )
{
     int ch;
     
     while( ( ch = getchar() ) != '\n' && ch != EOF );
}

ssharish

"Any fool can know, point is to understand"

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Join Date: Jul 2008

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ArkM

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Re: Pls help me with this Struct function

#10

Sep 28th, 2008

No portable solution of this problem in standard C. The C character stream stdin is not keyboard stream, you may attach it to a disk file, for example, and your program does not know about that fact. Really, as mentioned by Sci@phy, some compilers clear stdin stream buffer - VC, for example:
http://support.microsoft.com/kb/43993
But in this case you must clear BIOS keyboard input buffer too (see the article). Regrettably, no garantee that fflush(stdin) will supported by MS for the future compiler versions.

As far as no portable solutions, you can use, for example, non-standard <conio.h> header with old console i/o functions. Better don't mix stdio and conio input in that case (write some problem-oriented console i/o functions to compact and clear your code).

I have seen "good advices" to read stdin char by char until '\n' or EOF occured. I think, it's a bad idea: there are situations when user/program dialog hangs.

Yet another solution: don't worry, make a simple and clear interface - that's enough

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